diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 0453ce21..3b1d5a79 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -12,25 +12,6 @@ jobs:
           distribution: "temurin"
           java-version: "17"
       - run: 'sbt "; +scalafmtCheckAll; scalafmtSbtCheck" "; scalafixEnable; scalafix --check; test:scalafix --check"'
-  mimaReport:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: "actions/checkout@v3"
-      - uses: actions/setup-java@v3
-        with:
-          cache: "sbt"
-          distribution: "temurin"
-          java-version: ${{matrix.java}}
-      - run: 'sbt "++${{matrix.scala}} mimaReportBinaryIssues"'
-    strategy:
-      matrix:
-        java:
-          - "8"
-          - "11"
-          - "17"
-        scala:
-          - "2.11.12"
-          - "2.12.17"
   test:
     runs-on: ubuntu-latest
     steps:
@@ -44,12 +25,10 @@ jobs:
     strategy:
       matrix:
         java:
-          - "8"
           - "11"
           - "17"
         scala:
-          - "2.12.17"
-          - "2.13.8"
+          - "2.13.13"
   testWithCoverageReport:
     runs-on: ubuntu-latest
     steps:
diff --git a/.github/workflows/release-drafter.yml b/.github/workflows/release-drafter.yml
index ba091604..a83778ef 100644
--- a/.github/workflows/release-drafter.yml
+++ b/.github/workflows/release-drafter.yml
@@ -3,7 +3,7 @@ name: Release Drafter
 on:
   push:
     branches:
-      - develop
+      - dai/develop
 
 jobs:
   update_release_draft:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 9e85efaf..fa8bee3a 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -1,7 +1,7 @@
 name: Release
 on:
   push:
-    branches: [develop]
+    branches: [dai/develop]
     tags: ["*"]
 jobs:
   publish:
@@ -13,11 +13,9 @@ jobs:
           cache: "sbt"
           distribution: "temurin"
           java-version: "17"
-      - uses: olafurpg/setup-gpg@v3
       - name: Publish ${{ github.ref }}
-        run: sbt ci-release
+        run: sbt publish
         env:
-          PGP_PASSPHRASE: ${{ secrets.PGP_PASSPHRASE }}
-          PGP_SECRET: ${{ secrets.PGP_SECRET }}
-          SONATYPE_PASSWORD: ${{ secrets.SONATYPE_PASSWORD }}
-          SONATYPE_USERNAME: ${{ secrets.SONATYPE_USERNAME }}
+          NEXUS_HOST: "nexus.xebialabs.com"
+          NEXUS_USERNAME: ${{ secrets.NEXUS_CI_USER }}
+          NEXUS_PASSWORD: ${{ secrets.NEXUS_CI_USER_PWD }}
diff --git a/.gitignore b/.gitignore
index 7be56abe..03587590 100644
--- a/.gitignore
+++ b/.gitignore
@@ -45,3 +45,5 @@ project/build/target/
 project/plugins/target/
 project/plugins/lib_managed/
 project/plugins/src_managed/
+
+/.bsp
\ No newline at end of file
diff --git a/README.md b/README.md
index a9b99bb5..08558dd4 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,8 @@
 [![Latest version](https://index.scala-lang.org/twitter/chill/chill/latest.svg?color=orange)](https://index.scala-lang.org/twitter/chill/chill)
 [![Chat](https://badges.gitter.im/twitter/chill.svg)](https://gitter.im/twitter/chill?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
+IMPORTANT: This is Digital.ai fork of twitter/chill. Please do not use it in your projects unless you are Digital.ai employee. 
+
 Extensions for the [Kryo serialization library](https://github.com/EsotericSoftware/kryo) including
 serializers and a set of classes to ease configuration of Kryo in systems like Hadoop, Storm,
 Akka, etc.
diff --git a/build.sbt b/build.sbt
index 755831fe..fc8efc8d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,9 +1,7 @@
-import com.typesafe.tools.mima.plugin.MimaPlugin.mimaDefaultSettings
-
 val akkaVersion = "2.6.20"
 val algebirdVersion = "0.13.9"
 val bijectionVersion = "0.9.7"
-val kryoVersion = "4.0.2"
+val kryoVersion = "5.6.0"
 val scroogeVersion = "21.2.0"
 val asmVersion = "4.16"
 val protobufVersion = "3.22.2"
@@ -18,11 +16,12 @@ def scalaVersionSpecificFolders(srcBaseDir: java.io.File, scalaVersion: String):
   }
 
 val sharedSettings = Seq(
-  organization := "com.twitter",
-  scalaVersion := "2.11.12",
-  crossScalaVersions := Seq("2.11.12", "2.12.17", "2.13.8"),
+  organization := "com.xebialabs.chill",
+  scalaVersion := "2.13.13",
+  crossScalaVersions := Seq("2.11.12", "2.12.17", "2.13.13"),
   scalacOptions ++= Seq("-unchecked", "-deprecation"),
   scalacOptions ++= {
+    val credentialsFile = Path.userHome / ".sbt" / ".chill-credentials"
     scalaVersion.value match {
       case v if v.startsWith("2.11") => Seq("-Ywarn-unused", "-Ywarn-unused-import", "-target:jvm-1.8")
       case _                         => Seq("-Ywarn-unused", "-release", "8")
@@ -53,10 +52,10 @@ val sharedSettings = Seq(
     "org.scalacheck" %% "scalacheck" % "1.15.2" % "test",
     "org.scalatest" %% "scalatest" % "3.2.15" % "test",
     "org.scalatestplus" %% "scalatestplus-scalacheck" % "3.1.0.0-RC2" % "test",
-    "com.esotericsoftware" % "kryo-shaded" % kryoVersion
+    "com.esotericsoftware" % "kryo5" % kryoVersion
   ),
   Test / parallelExecution := true,
-  pomExtra := <url>https://github.com/twitter/chill</url>
+  pomExtra := <url>https://github.com/xebialabs/chill</url>
         <licenses>
       <license>
       <name>Apache 2</name>
@@ -98,14 +97,12 @@ lazy val chillAll = Project(
 ).settings(sharedSettings)
   .settings(noPublishSettings)
   .settings(
-    mimaPreviousArtifacts := Set.empty,
     crossScalaVersions := Nil
   )
   .aggregate(
     chill,
     chillBijection,
     chillScrooge,
-    chillStorm,
     chillJava,
     chillHadoop,
     chillThrift,
@@ -123,40 +120,8 @@ lazy val noPublishSettings = Seq(
   publishArtifact := false
 )
 
-/**
- * This returns the youngest jar we released that is compatible with the current.
- */
 val unreleasedModules = Set[String]("akka")
-val javaOnly = Set[String]("storm", "java", "hadoop", "thrift", "protobuf")
-val binaryCompatVersion = "0.9.2"
-
-def youngestForwardCompatible(subProj: String) =
-  Some(subProj)
-    .filterNot(unreleasedModules.contains)
-    .map { s =>
-      if (javaOnly.contains(s))
-        "com.twitter" % ("chill-" + s) % binaryCompatVersion
-      else
-        "com.twitter" %% ("chill-" + s) % binaryCompatVersion
-    }
-
-val ignoredABIProblems = {
-  import com.typesafe.tools.mima.core._
-  import com.typesafe.tools.mima.core.ProblemFilters._
-  Seq(
-    exclude[MissingTypesProblem]("com.twitter.chill.storm.BlizzardKryoFactory"),
-    exclude[MissingTypesProblem]("com.twitter.chill.InnerClosureFinder"),
-    exclude[IncompatibleResultTypeProblem]("com.twitter.chill.InnerClosureFinder.visitMethod"),
-    exclude[IncompatibleResultTypeProblem]("com.twitter.chill.FieldAccessFinder.visitMethod"),
-    exclude[MissingClassProblem]("com.twitter.chill.FieldAccessFinder"),
-    exclude[MissingTypesProblem]("com.twitter.chill.FieldAccessFinder"),
-    exclude[DirectMissingMethodProblem]("com.twitter.chill.FieldAccessFinder.this"),
-    exclude[IncompatibleResultTypeProblem]("com.twitter.chill.Tuple1*Serializer.read"),
-    exclude[IncompatibleMethTypeProblem]("com.twitter.chill.Tuple1*Serializer.write"),
-    exclude[IncompatibleResultTypeProblem]("com.twitter.chill.Tuple2*Serializer.read"),
-    exclude[IncompatibleMethTypeProblem]("com.twitter.chill.Tuple2*Serializer.write")
-  )
-}
+val javaOnly = Set[String]("java", "hadoop", "thrift", "protobuf")
 
 def module(name: String) = {
   val id = "chill-%s".format(name)
@@ -164,8 +129,6 @@ def module(name: String) = {
     .settings(sharedSettings)
     .settings(
       Keys.name := id,
-      mimaPreviousArtifacts := youngestForwardCompatible(name).toSet,
-      mimaBinaryIssueFilters ++= ignoredABIProblems,
       // Disable cross publishing for java artifacts
       publishArtifact :=
         (if (javaOnly.contains(name) && scalaVersion.value.startsWith("2.11")) false else true)
@@ -180,8 +143,6 @@ lazy val chill = Project(
 ).settings(sharedSettings)
   .settings(
     name := "chill",
-    mimaPreviousArtifacts := Set("com.twitter" %% "chill" % binaryCompatVersion),
-    mimaBinaryIssueFilters ++= ignoredABIProblems,
     libraryDependencies += "org.apache.xbean" % "xbean-asm7-shaded" % asmVersion
   )
   .dependsOn(chillJava)
@@ -216,15 +177,6 @@ lazy val chillJava = module("java").settings(
   autoScalaLibrary := false
 )
 
-// This can only have java deps!
-lazy val chillStorm = module("storm")
-  .settings(
-    crossPaths := false,
-    autoScalaLibrary := false,
-    libraryDependencies += "org.apache.storm" % "storm-core" % "2.4.0" % "provided"
-  )
-  .dependsOn(chillJava)
-
 // This can only have java deps!
 lazy val chillHadoop = module("hadoop")
   .settings(
@@ -284,3 +236,23 @@ lazy val chillAlgebird = module("algebird")
     )
   )
   .dependsOn(chill)
+
+ThisBuild / dynverSeparator := "-"
+ThisBuild / dynverSonatypeSnapshots := true
+ThisBuild / publishMavenStyle := true
+
+ThisBuild / publishTo := {
+  val nexus = "https://nexus.xebialabs.com/nexus/content/"
+  if (isSnapshot.value)
+    Some("snapshots".at(nexus + "repositories/snapshots"))
+  else
+    Some("releases".at(nexus + "repositories/releases"))
+}
+
+inThisBuild(
+  List(
+    scalaVersion := "2.13.13",
+    semanticdbEnabled := true,
+    semanticdbVersion := scalafixSemanticdb.revision
+  )
+)
diff --git a/chill-akka/src/main/scala/com/twitter/chill/akka/ActorRefSerializer.scala b/chill-akka/src/main/scala/com/twitter/chill/akka/ActorRefSerializer.scala
index 365a2ef8..329382a2 100644
--- a/chill-akka/src/main/scala/com/twitter/chill/akka/ActorRefSerializer.scala
+++ b/chill-akka/src/main/scala/com/twitter/chill/akka/ActorRefSerializer.scala
@@ -14,8 +14,8 @@ package com.twitter.chill.akka
  */
 import akka.actor.{ActorPath, ActorRef, ExtendedActorSystem}
 import akka.serialization.Serialization
-import com.esotericsoftware.kryo.{Kryo, Serializer}
-import com.esotericsoftware.kryo.io.{Input, Output}
+import com.esotericsoftware.kryo.kryo5.{Kryo, Serializer}
+import com.esotericsoftware.kryo.kryo5.io.{Input, Output}
 
 import com.twitter.chill.{toRich, IKryoRegistrar}
 
@@ -34,7 +34,7 @@ class ActorRefSerializer(system: ExtendedActorSystem) extends Serializer[ActorRe
       kryo.forSubclass[ActorRef](this)
     }
 
-  override def read(kryo: Kryo, input: Input, typ: Class[ActorRef]): ActorRef = {
+  override def read(kryo: Kryo, input: Input, typ: Class[_ <: ActorRef]): ActorRef = {
     val path = ActorPath.fromString(input.readString())
     system.provider.resolveActorRef(path)
   }
diff --git a/chill-algebird/src/main/scala/com/twitter/chill/algebird/AlgebirdRegistrar.scala b/chill-algebird/src/main/scala/com/twitter/chill/algebird/AlgebirdRegistrar.scala
index 4aa6d737..ec5baac9 100644
--- a/chill-algebird/src/main/scala/com/twitter/chill/algebird/AlgebirdRegistrar.scala
+++ b/chill-algebird/src/main/scala/com/twitter/chill/algebird/AlgebirdRegistrar.scala
@@ -15,8 +15,8 @@ limitations under the License.
  */
 package com.twitter.chill.algebird
 
-import com.esotericsoftware.kryo.Kryo
-import com.esotericsoftware.kryo.serializers.FieldSerializer
+import com.esotericsoftware.kryo.kryo5.Kryo
+import com.esotericsoftware.kryo.kryo5.serializers.FieldSerializer
 
 import com.twitter.chill.IKryoRegistrar
 
diff --git a/chill-algebird/src/main/scala/com/twitter/chill/algebird/AlgebirdSerializers.scala b/chill-algebird/src/main/scala/com/twitter/chill/algebird/AlgebirdSerializers.scala
index 59f13e93..030633b1 100644
--- a/chill-algebird/src/main/scala/com/twitter/chill/algebird/AlgebirdSerializers.scala
+++ b/chill-algebird/src/main/scala/com/twitter/chill/algebird/AlgebirdSerializers.scala
@@ -15,9 +15,9 @@ limitations under the License.
  */
 package com.twitter.chill.algebird
 
-import com.esotericsoftware.kryo.Kryo
-import com.esotericsoftware.kryo.{Serializer => KSerializer}
-import com.esotericsoftware.kryo.io.{Input, Output}
+import com.esotericsoftware.kryo.kryo5.Kryo
+import com.esotericsoftware.kryo.kryo5.{Serializer => KSerializer}
+import com.esotericsoftware.kryo.kryo5.io.{Input, Output}
 
 import com.twitter.algebird.{AveragedValue, DecayedValue, HLL, HyperLogLog, HyperLogLogMonoid, Moments, QTree}
 
@@ -29,7 +29,7 @@ class AveragedValueSerializer extends KSerializer[AveragedValue] {
     out.writeLong(s.count, true)
     out.writeDouble(s.value)
   }
-  def read(kser: Kryo, in: Input, cls: Class[AveragedValue]): AveragedValue =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: AveragedValue]): AveragedValue =
     AveragedValue(in.readLong(true), in.readDouble)
 }
 
@@ -42,7 +42,7 @@ class MomentsSerializer extends KSerializer[Moments] {
     out.writeDouble(s.m3)
     out.writeDouble(s.m4)
   }
-  def read(kser: Kryo, in: Input, cls: Class[Moments]): Moments =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Moments]): Moments =
     Moments(in.readLong(true), in.readDouble, in.readDouble, in.readDouble, in.readDouble)
 }
 
@@ -52,7 +52,7 @@ class DecayedValueSerializer extends KSerializer[DecayedValue] {
     out.writeDouble(s.value)
     out.writeDouble(s.scaledTime)
   }
-  def read(kser: Kryo, in: Input, cls: Class[DecayedValue]): DecayedValue =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: DecayedValue]): DecayedValue =
     DecayedValue(in.readDouble, in.readDouble)
 }
 
@@ -63,7 +63,7 @@ class HLLSerializer extends KSerializer[HLL] {
     out.writeInt(bytes.size, true)
     out.writeBytes(bytes)
   }
-  def read(kser: Kryo, in: Input, cls: Class[HLL]): HLL =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: HLL]): HLL =
     HyperLogLog.fromBytes(in.readBytes(in.readInt(true)))
 }
 
@@ -72,7 +72,7 @@ class HLLMonoidSerializer extends KSerializer[HyperLogLogMonoid] {
   val hllMonoids: MMap[Int, HyperLogLogMonoid] = MMap[Int, HyperLogLogMonoid]()
   def write(kser: Kryo, out: Output, mon: HyperLogLogMonoid): Unit =
     out.writeInt(mon.bits, true)
-  def read(kser: Kryo, in: Input, cls: Class[HyperLogLogMonoid]): HyperLogLogMonoid = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: HyperLogLogMonoid]): HyperLogLogMonoid = {
     val bits = in.readInt(true)
     hllMonoids.getOrElseUpdate(bits, new HyperLogLogMonoid(bits))
   }
@@ -80,7 +80,7 @@ class HLLMonoidSerializer extends KSerializer[HyperLogLogMonoid] {
 
 class QTreeSerializer extends KSerializer[QTree[Any]] {
   setImmutable(true)
-  override def read(kryo: Kryo, input: Input, cls: Class[QTree[Any]]): QTree[Any] = {
+  override def read(kryo: Kryo, input: Input, cls: Class[_ <: QTree[Any]]): QTree[Any] = {
     val (v1, v2, v3) = (input.readLong(), input.readInt(), input.readLong())
     val v4 = kryo.readClassAndObject(input)
     val v5 = kryo.readClassAndObject(input).asInstanceOf[Option[QTree[Any]]]
diff --git a/chill-avro/src/test/java/com/twitter/chill/avro/AvroSerializerJavaTest.java b/chill-avro/src/test/java/com/twitter/chill/avro/AvroSerializerJavaTest.java
index 921c44cc..62a258e3 100644
--- a/chill-avro/src/test/java/com/twitter/chill/avro/AvroSerializerJavaTest.java
+++ b/chill-avro/src/test/java/com/twitter/chill/avro/AvroSerializerJavaTest.java
@@ -1,8 +1,9 @@
 package com.twitter.chill.avro;
 
 import avro.FiscalRecord;
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy;
 import com.twitter.chill.KryoInstantiator;
 import com.twitter.chill.KryoPool;
 import org.apache.avro.Schema;
@@ -11,7 +12,6 @@
 import org.apache.avro.generic.GenericRecordBuilder;
 import org.junit.Before;
 import org.junit.Test;
-import org.objenesis.strategy.StdInstantiatorStrategy;
 import scala.reflect.ClassTag;
 
 import static org.junit.Assert.assertEquals;
diff --git a/chill-bijection/src/main/scala/com/twitter/chill/BijectionEnrichedKryo.scala b/chill-bijection/src/main/scala/com/twitter/chill/BijectionEnrichedKryo.scala
index aafd195d..1808807e 100644
--- a/chill-bijection/src/main/scala/com/twitter/chill/BijectionEnrichedKryo.scala
+++ b/chill-bijection/src/main/scala/com/twitter/chill/BijectionEnrichedKryo.scala
@@ -16,7 +16,6 @@ limitations under the License.
 
 package com.twitter.chill
 
-import com.twitter.bijection.Injection
 import com.twitter.bijection.{Bijection, Bufferable, ImplicitBijection, Injection}
 
 import scala.reflect.ClassTag
@@ -32,7 +31,7 @@ object BijectionEnrichedKryo {
   )(implicit bij: ImplicitBijection[A, B], cmf: ClassTag[B]): KSerializer[A] =
     new KSerializer[A] {
       def write(k: Kryo, out: Output, obj: A): Unit = kser.write(k, out, bij(obj))
-      def read(k: Kryo, in: Input, cls: Class[A]): A =
+      def read(k: Kryo, in: Input, cls: Class[_ <: A]): A =
         bij.invert(kser.read(k, in, cmf.runtimeClass.asInstanceOf[Class[B]]))
     }
 
diff --git a/chill-bijection/src/main/scala/com/twitter/chill/InjectiveSerializer.scala b/chill-bijection/src/main/scala/com/twitter/chill/InjectiveSerializer.scala
index fce22244..4d4db9d9 100644
--- a/chill-bijection/src/main/scala/com/twitter/chill/InjectiveSerializer.scala
+++ b/chill-bijection/src/main/scala/com/twitter/chill/InjectiveSerializer.scala
@@ -29,7 +29,7 @@ class InjectiveSerializer[T] private (injection: Injection[T, Array[Byte]])
     out.writeBytes(bytes)
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[T]): T = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: T]): T = {
     val bytes = new Array[Byte](in.readInt(true))
     in.readBytes(bytes)
     injection.invert(bytes).get
diff --git a/chill-bijection/src/test/scala/com/twitter/chill/ExternalizerCodecSpec.scala b/chill-bijection/src/test/scala/com/twitter/chill/ExternalizerCodecSpec.scala
index 89a28f1b..886ed973 100644
--- a/chill-bijection/src/test/scala/com/twitter/chill/ExternalizerCodecSpec.scala
+++ b/chill-bijection/src/test/scala/com/twitter/chill/ExternalizerCodecSpec.scala
@@ -17,19 +17,19 @@
 package com.twitter.chill
 
 import com.twitter.bijection.Injection
-import scala.util.Try
 import org.scalatest.wordspec.AnyWordSpec
 
+import scala.util.Try
+
 class NotSerializable {
   val x = "abcd"
   override def equals(other: Any): Boolean =
     other match {
-      case i: NotSerializable => true
+      case _: NotSerializable => true
       case _                  => false
     }
 }
 class ExternalizerCodecSpec extends AnyWordSpec {
-  import ExternalizerCodec._
   import ExternalizerInjection._
 
   def rt[T: ExternalizerInjection: ExternalizerCodec](t: T): Try[T] = {
diff --git a/chill-hadoop/src/main/java/com/twitter/chill/hadoop/KryoSerialization.java b/chill-hadoop/src/main/java/com/twitter/chill/hadoop/KryoSerialization.java
index 29d1dc5a..886790da 100644
--- a/chill-hadoop/src/main/java/com/twitter/chill/hadoop/KryoSerialization.java
+++ b/chill-hadoop/src/main/java/com/twitter/chill/hadoop/KryoSerialization.java
@@ -16,15 +16,15 @@
 
 package com.twitter.chill.hadoop;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.io.Output;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy;
 
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.conf.Configured;
 import org.apache.hadoop.io.serializer.Deserializer;
 import org.apache.hadoop.io.serializer.Serialization;
 import org.apache.hadoop.io.serializer.Serializer;
-import org.objenesis.strategy.StdInstantiatorStrategy;
 
 import com.twitter.chill.KryoPool;
 import com.twitter.chill.KryoInstantiator;
diff --git a/chill-hadoop/src/test/scala/com/twitter/chill/hadoop/HadoopTests.scala b/chill-hadoop/src/test/scala/com/twitter/chill/hadoop/HadoopTests.scala
index 97f9cde8..0d931e1d 100644
--- a/chill-hadoop/src/test/scala/com/twitter/chill/hadoop/HadoopTests.scala
+++ b/chill-hadoop/src/test/scala/com/twitter/chill/hadoop/HadoopTests.scala
@@ -16,9 +16,8 @@ limitations under the License.
 
 package com.twitter.chill.hadoop
 
-import com.esotericsoftware.kryo.Kryo
-
-import org.objenesis.strategy.StdInstantiatorStrategy
+import com.esotericsoftware.kryo.kryo5.Kryo
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy;
 
 import java.io.{ByteArrayInputStream => BAIn, ByteArrayOutputStream => BAOut}
 import org.apache.hadoop.conf.Configuration
@@ -28,9 +27,18 @@ import com.twitter.chill.KryoInstantiator
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpec
 
+class AnyKryoInstantiator extends KryoInstantiator {
+  override def newKryo: Kryo = {
+    val k = new Kryo
+    k.register(Class.forName("com.twitter.chill.hadoop.HadoopTests"))
+    k.register(Class.forName("scala.collection.immutable.List"))
+    k
+  }
+}
 class StdKryoInstantiator extends KryoInstantiator {
   override def newKryo: Kryo = {
     val k = new Kryo
+    k.register(Class.forName("scala.Tuple2$mcII$sp"))
     k.setInstantiatorStrategy(new StdInstantiatorStrategy)
     k
   }
@@ -56,7 +64,7 @@ class HadoopTests extends AnyWordSpec with Matchers {
     "accept anything" in {
       val conf = new Configuration
       val hc = new HadoopConfig(conf)
-      ConfiguredInstantiator.setReflect(hc, classOf[KryoInstantiator])
+      ConfiguredInstantiator.setReflect(hc, classOf[AnyKryoInstantiator])
 
       val ks = new KryoSerialization(conf)
       Seq(classOf[List[_]], classOf[Int], this.getClass).forall { cls =>
diff --git a/chill-java/src/main/java/com/twitter/chill/ClassRegistrar.java b/chill-java/src/main/java/com/twitter/chill/ClassRegistrar.java
index 9a1aac9d..4130d9a7 100644
--- a/chill-java/src/main/java/com/twitter/chill/ClassRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/ClassRegistrar.java
@@ -16,7 +16,7 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.kryo5.Kryo;
 
 /** Register this class to be used with the default serializer for this class */
 public class ClassRegistrar<T> implements IKryoRegistrar {
diff --git a/chill-java/src/main/java/com/twitter/chill/IKryoRegistrar.java b/chill-java/src/main/java/com/twitter/chill/IKryoRegistrar.java
index 25a95076..0d4bf35d 100644
--- a/chill-java/src/main/java/com/twitter/chill/IKryoRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/IKryoRegistrar.java
@@ -16,7 +16,7 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.kryo5.Kryo;
 import java.io.Serializable;
 
 /**
diff --git a/chill-java/src/main/java/com/twitter/chill/KryoInstantiator.java b/chill-java/src/main/java/com/twitter/chill/KryoInstantiator.java
index 5af3aa21..1e2da834 100644
--- a/chill-java/src/main/java/com/twitter/chill/KryoInstantiator.java
+++ b/chill-java/src/main/java/com/twitter/chill/KryoInstantiator.java
@@ -16,8 +16,8 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
-import org.objenesis.strategy.InstantiatorStrategy;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.InstantiatorStrategy;
 import java.io.Serializable;
 
 /** Class to create a new Kryo instance.
diff --git a/chill-java/src/main/java/com/twitter/chill/KryoPool.java b/chill-java/src/main/java/com/twitter/chill/KryoPool.java
index ce15cb66..eb79a889 100644
--- a/chill-java/src/main/java/com/twitter/chill/KryoPool.java
+++ b/chill-java/src/main/java/com/twitter/chill/KryoPool.java
@@ -16,9 +16,9 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import java.io.OutputStream;
 import java.io.ByteArrayOutputStream;
diff --git a/chill-java/src/main/java/com/twitter/chill/ReflectingDefaultRegistrar.java b/chill-java/src/main/java/com/twitter/chill/ReflectingDefaultRegistrar.java
index 7ace7507..ea149925 100644
--- a/chill-java/src/main/java/com/twitter/chill/ReflectingDefaultRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/ReflectingDefaultRegistrar.java
@@ -16,8 +16,8 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
 
 /** Set the default serializers for subclasses of the given class
  */
diff --git a/chill-java/src/main/java/com/twitter/chill/ReflectingRegistrar.java b/chill-java/src/main/java/com/twitter/chill/ReflectingRegistrar.java
index e55fa04b..fa716fa3 100644
--- a/chill-java/src/main/java/com/twitter/chill/ReflectingRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/ReflectingRegistrar.java
@@ -16,9 +16,9 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.util.Util;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.util.Util;
 
 /** Use reflection to instantiate a serializer.
  * Used when serializer classes are written to config files
diff --git a/chill-java/src/main/java/com/twitter/chill/SerDeState.java b/chill-java/src/main/java/com/twitter/chill/SerDeState.java
index 24cd403c..0796641e 100644
--- a/chill-java/src/main/java/com/twitter/chill/SerDeState.java
+++ b/chill-java/src/main/java/com/twitter/chill/SerDeState.java
@@ -16,9 +16,9 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import java.io.OutputStream;
 import java.io.InputStream;
@@ -43,7 +43,7 @@ protected SerDeState(Kryo k, Input in, Output out) {
   /** Call this when to reset the state to the initial state */
   public void clear() {
     input.setBuffer(EMPTY_BUFFER);
-    output.clear();
+    output.reset();
   }
 
   public void setInput(byte[] in) { input.setBuffer(in); }
diff --git a/chill-java/src/main/java/com/twitter/chill/SingleDefaultRegistrar.java b/chill-java/src/main/java/com/twitter/chill/SingleDefaultRegistrar.java
index b11b4573..4fd738db 100644
--- a/chill-java/src/main/java/com/twitter/chill/SingleDefaultRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/SingleDefaultRegistrar.java
@@ -16,8 +16,8 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
 
 /** Set the default serializers for subclasses of the given class
  */
diff --git a/chill-java/src/main/java/com/twitter/chill/SingleRegistrar.java b/chill-java/src/main/java/com/twitter/chill/SingleRegistrar.java
index f449339b..680dc662 100644
--- a/chill-java/src/main/java/com/twitter/chill/SingleRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/SingleRegistrar.java
@@ -16,8 +16,8 @@
 
 package com.twitter.chill;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
 
 public class SingleRegistrar<T> implements IKryoRegistrar {
   final Class<T> klass;
diff --git a/chill-java/src/main/java/com/twitter/chill/config/ConfiguredInstantiator.java b/chill-java/src/main/java/com/twitter/chill/config/ConfiguredInstantiator.java
index d526e706..866615fb 100644
--- a/chill-java/src/main/java/com/twitter/chill/config/ConfiguredInstantiator.java
+++ b/chill-java/src/main/java/com/twitter/chill/config/ConfiguredInstantiator.java
@@ -20,9 +20,9 @@
 
 import java.lang.reflect.InvocationTargetException;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 /**
  * This is the standard Config based KryoInstantiator.
diff --git a/chill-java/src/main/java/com/twitter/chill/config/ReflectingInstantiator.java b/chill-java/src/main/java/com/twitter/chill/config/ReflectingInstantiator.java
index 7ba42b63..b1baf6c2 100644
--- a/chill-java/src/main/java/com/twitter/chill/config/ReflectingInstantiator.java
+++ b/chill-java/src/main/java/com/twitter/chill/config/ReflectingInstantiator.java
@@ -22,10 +22,10 @@
 import com.twitter.chill.ReflectingRegistrar;
 import com.twitter.chill.ReflectingDefaultRegistrar;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import org.objenesis.strategy.InstantiatorStrategy;
-import org.objenesis.strategy.StdInstantiatorStrategy;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.InstantiatorStrategy;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy;
 import java.util.ArrayList;
 import java.util.List;
 import java.lang.reflect.InvocationTargetException;
diff --git a/chill-java/src/main/java/com/twitter/chill/java/ArraysAsListSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/ArraysAsListSerializer.java
index f4811d95..68818bec 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/ArraysAsListSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/ArraysAsListSerializer.java
@@ -26,10 +26,10 @@
 import java.util.HashMap;
 import java.util.Map;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 /**
  * A kryo {@link Serializer} for lists created via {@link Arrays#asList(Object...)}.
@@ -71,7 +71,7 @@ public ArraysAsListSerializer() {
     }
 
     @Override
-    public List<?> read(final Kryo kryo, final Input input, final Class<List<?>> type) {
+    public List<?> read(final Kryo kryo, final Input input, final Class<? extends List<?>> type) {
         final int length = input.readInt(true);
         Class<?> componentType = kryo.readClass(input).getType();
         try {
diff --git a/chill-java/src/main/java/com/twitter/chill/java/BitSetSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/BitSetSerializer.java
index 597699c6..b7bb618a 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/BitSetSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/BitSetSerializer.java
@@ -16,11 +16,11 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.KryoException;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.KryoException;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
@@ -81,7 +81,7 @@ public void write(Kryo kryo, Output output, BitSet bitSet) {
     }
 
     @Override
-    public BitSet read(Kryo kryo, Input input, Class<BitSet> bitSetClass) {
+    public BitSet read(Kryo kryo, Input input, Class<? extends BitSet> bitSetClass) {
         int len = input.readInt(true);
         long[] target = new long[len];
 
diff --git a/chill-java/src/main/java/com/twitter/chill/java/InetSocketAddressSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/InetSocketAddressSerializer.java
index c1515853..757377ee 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/InetSocketAddressSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/InetSocketAddressSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
@@ -39,7 +39,7 @@ public void write(Kryo kryo, Output output, InetSocketAddress obj) {
   }
 
   @Override
-  public InetSocketAddress read(Kryo kryo, Input input, Class<InetSocketAddress> klass) {
+  public InetSocketAddress read(Kryo kryo, Input input, Class<? extends InetSocketAddress> klass) {
     String host = input.readString();
     int port = input.readInt(true);
     return new InetSocketAddress(host, port);
diff --git a/chill-java/src/main/java/com/twitter/chill/java/IterableRegistrar.java b/chill-java/src/main/java/com/twitter/chill/java/IterableRegistrar.java
index e5ad1ea7..9f42c1bc 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/IterableRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/IterableRegistrar.java
@@ -18,8 +18,8 @@
 
 import com.twitter.chill.IKryoRegistrar;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.DefaultSerializer;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.DefaultSerializer;
 
 import java.util.Arrays;
 
diff --git a/chill-java/src/main/java/com/twitter/chill/java/IterableRegistrarSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/IterableRegistrarSerializer.java
index de61fe8b..3a6e2964 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/IterableRegistrarSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/IterableRegistrarSerializer.java
@@ -17,10 +17,10 @@
 package com.twitter.chill.java;
 
 import com.twitter.chill.IKryoRegistrar;
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
-import com.esotericsoftware.kryo.Serializer;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
+import com.esotericsoftware.kryo.kryo5.Serializer;
 
 import java.util.ArrayList;
 
@@ -32,7 +32,7 @@ public void write(Kryo kryo, Output output, IterableRegistrar obj) {
     }
     kryo.writeClassAndObject(output, null);
   }
-  public IterableRegistrar read(Kryo kryo, Input input, Class<IterableRegistrar> type) {
+  public IterableRegistrar read(Kryo kryo, Input input, Class<? extends IterableRegistrar> type) {
     ArrayList<IKryoRegistrar> krs = new ArrayList<IKryoRegistrar>();
     IKryoRegistrar thisKr = (IKryoRegistrar)kryo.readClassAndObject(input);
     while(thisKr != null) {
diff --git a/chill-java/src/main/java/com/twitter/chill/java/Java8ClosureRegistrar.java b/chill-java/src/main/java/com/twitter/chill/java/Java8ClosureRegistrar.java
index dea99914..d8a87b89 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/Java8ClosureRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/Java8ClosureRegistrar.java
@@ -1,7 +1,7 @@
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.serializers.ClosureSerializer;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.serializers.ClosureSerializer;
 import com.twitter.chill.IKryoRegistrar;
 
 /**
diff --git a/chill-java/src/main/java/com/twitter/chill/java/LocaleSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/LocaleSerializer.java
index aa769aa7..cd6fbef0 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/LocaleSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/LocaleSerializer.java
@@ -16,11 +16,11 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.serializers.JavaSerializer;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
diff --git a/chill-java/src/main/java/com/twitter/chill/java/PackageRegistrar.java b/chill-java/src/main/java/com/twitter/chill/java/PackageRegistrar.java
index 21d1ebf2..fce8e307 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/PackageRegistrar.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/PackageRegistrar.java
@@ -18,7 +18,7 @@
 
 import com.twitter.chill.IKryoRegistrar;
 
-import com.esotericsoftware.kryo.Kryo;
+import com.esotericsoftware.kryo.kryo5.Kryo;
 
 import java.util.ArrayList;
 
diff --git a/chill-java/src/main/java/com/twitter/chill/java/PriorityQueueSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/PriorityQueueSerializer.java
index c9dd95fd..1d3de4dd 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/PriorityQueueSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/PriorityQueueSerializer.java
@@ -19,10 +19,10 @@
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import java.lang.reflect.Field;
 import java.util.PriorityQueue;
@@ -62,7 +62,7 @@ public void write(Kryo k, Output o, PriorityQueue<?> q) {
       o.flush();
     }
   }
-  public PriorityQueue<?> read(Kryo k, Input i, Class<PriorityQueue<?>> c) {
+  public PriorityQueue<?> read(Kryo k, Input i, Class<? extends PriorityQueue<?>> c) {
     Comparator<Object> comp = (Comparator<Object>)k.readClassAndObject(i);
     int sz = i.readInt(true);
     // can't create with size 0:
diff --git a/chill-java/src/main/java/com/twitter/chill/java/RegexSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/RegexSerializer.java
index 2f9742ab..168bb78d 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/RegexSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/RegexSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
@@ -38,7 +38,7 @@ public void write(Kryo kryo, Output output, Pattern pattern) {
     }
 
     @Override
-    public Pattern read(Kryo kryo, Input input, Class<Pattern> patternClass) {
+    public Pattern read(Kryo kryo, Input input, Class<? extends Pattern> patternClass) {
         return Pattern.compile(input.readString());
     }
 }
diff --git a/chill-java/src/main/java/com/twitter/chill/java/SimpleDateFormatSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/SimpleDateFormatSerializer.java
index f3711a30..d5a4b28e 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/SimpleDateFormatSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/SimpleDateFormatSerializer.java
@@ -16,7 +16,7 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.serializers.JavaSerializer;
+import com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
diff --git a/chill-java/src/main/java/com/twitter/chill/java/SqlDateSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/SqlDateSerializer.java
index d31061df..d93a9d51 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/SqlDateSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/SqlDateSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
@@ -38,7 +38,7 @@ public void write(Kryo kryo, Output output, Date date) {
     }
 
     @Override
-    public Date read(Kryo kryo, Input input, Class<Date> dateClass) {
+    public Date read(Kryo kryo, Input input, Class<? extends Date> dateClass) {
         return new Date(input.readLong(true));
     }
 }
diff --git a/chill-java/src/main/java/com/twitter/chill/java/SqlTimeSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/SqlTimeSerializer.java
index eeb5e938..0f613544 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/SqlTimeSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/SqlTimeSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
@@ -38,7 +38,7 @@ public void write(Kryo kryo, Output output, Time time) {
     }
 
     @Override
-    public Time read(Kryo kryo, Input input, Class<Time> timeClass) {
+    public Time read(Kryo kryo, Input input, Class<? extends Time> timeClass) {
         return new Time(input.readLong(true));
     }
 }
diff --git a/chill-java/src/main/java/com/twitter/chill/java/TimestampSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/TimestampSerializer.java
index f99f692e..99887e31 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/TimestampSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/TimestampSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
@@ -39,7 +39,7 @@ public void write(Kryo kryo, Output output, Timestamp timestamp) {
     }
 
     @Override
-    public Timestamp read(Kryo kryo, Input input, Class<Timestamp> timestampClass) {
+    public Timestamp read(Kryo kryo, Input input, Class<? extends Timestamp> timestampClass) {
         Timestamp ts = new Timestamp(input.readLong(true));
         ts.setNanos(input.readInt(true));
         return ts;
diff --git a/chill-java/src/main/java/com/twitter/chill/java/URISerializer.java b/chill-java/src/main/java/com/twitter/chill/java/URISerializer.java
index cfd53318..901948ae 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/URISerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/URISerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
@@ -38,7 +38,7 @@ public void write(Kryo kryo, Output output, URI uri) {
     }
 
     @Override
-    public URI read(Kryo kryo, Input input, Class<URI> uriClass) {
+    public URI read(Kryo kryo, Input input, Class<? extends URI> uriClass) {
         return URI.create(input.readString());
     }
 }
diff --git a/chill-java/src/main/java/com/twitter/chill/java/UUIDSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/UUIDSerializer.java
index 344c58c3..3ec1e76b 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/UUIDSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/UUIDSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
@@ -38,7 +38,7 @@ public void write(Kryo kryo, Output output, UUID uuid) {
         output.writeLong(uuid.getLeastSignificantBits(), false);
     }
 
-    @Override public UUID read(Kryo kryo, Input input, Class<UUID> uuidClass) {
+    @Override public UUID read(Kryo kryo, Input input, Class<? extends UUID> uuidClass) {
         return new UUID(input.readLong(false), input.readLong(false));
     }
 }
diff --git a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableCollectionSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableCollectionSerializer.java
index 0a1c6210..b48fd2a5 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableCollectionSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableCollectionSerializer.java
@@ -17,10 +17,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
 
diff --git a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableJavaCollectionSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableJavaCollectionSerializer.java
index cd5d8278..800d081e 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableJavaCollectionSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableJavaCollectionSerializer.java
@@ -17,10 +17,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import java.lang.reflect.Field;
 import java.util.Collection;
@@ -54,7 +54,7 @@ abstract class UnmodifiableJavaCollectionSerializer<T> extends Serializer<T> {
   
   @Override
   @SuppressWarnings("unchecked")
-  public T read(Kryo kryo, Input input, Class<T> type) {
+  public T read(Kryo kryo, Input input, Class<? extends T> type) {
     try {
       T u = (T) kryo.readClassAndObject(input);
       return newInstance(u);
diff --git a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableListSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableListSerializer.java
index 4c588d7f..a9f4ca77 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableListSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableListSerializer.java
@@ -17,10 +17,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
 
diff --git a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableMapSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableMapSerializer.java
index 839f33f3..1b8e2da4 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableMapSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableMapSerializer.java
@@ -17,10 +17,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
 
diff --git a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSetSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSetSerializer.java
index ed9b7491..d6699b2e 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSetSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSetSerializer.java
@@ -17,10 +17,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
 
diff --git a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSortedMapSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSortedMapSerializer.java
index c08b6792..6887f646 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSortedMapSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSortedMapSerializer.java
@@ -17,10 +17,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
 
diff --git a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSortedSetSerializer.java b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSortedSetSerializer.java
index 9cdc33e2..14f1772b 100644
--- a/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSortedSetSerializer.java
+++ b/chill-java/src/main/java/com/twitter/chill/java/UnmodifiableSortedSetSerializer.java
@@ -17,10 +17,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
 
diff --git a/chill-java/src/test/java/com/twitter/chill/java/TestCollections.java b/chill-java/src/test/java/com/twitter/chill/java/TestCollections.java
index 6c86334a..c44c563c 100644
--- a/chill-java/src/test/java/com/twitter/chill/java/TestCollections.java
+++ b/chill-java/src/test/java/com/twitter/chill/java/TestCollections.java
@@ -17,9 +17,9 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import java.util.*;
 
@@ -43,8 +43,14 @@ public class TestCollections {
         test_map.put(4, "four");
     }
 
-    public static <T> T serializeAndDeserialize(T t) {
+    public static <T> T serializeAndDeserialize(T t) throws ClassNotFoundException {
         Output output = new Output(1000, -1);
+        kryo.register(Class.forName("java.util.ArrayList"));
+        kryo.register(Class.forName("java.util.LinkedList"));
+        kryo.register(Class.forName("java.util.HashMap"));
+        kryo.register(Class.forName("java.util.TreeMap"));
+        kryo.register(Class.forName("java.util.HashSet"));
+        kryo.register(Class.forName("java.util.TreeSet"));
         kryo.writeClassAndObject(output, t);
         Input input = new Input(output.toBytes());
         return (T) kryo.readClassAndObject(input);
diff --git a/chill-java/src/test/java/com/twitter/chill/java/TestLists.java b/chill-java/src/test/java/com/twitter/chill/java/TestLists.java
index 1efe820c..a5d3c540 100644
--- a/chill-java/src/test/java/com/twitter/chill/java/TestLists.java
+++ b/chill-java/src/test/java/com/twitter/chill/java/TestLists.java
@@ -17,9 +17,9 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import java.util.Arrays;
 import java.util.HashMap;
@@ -51,8 +51,9 @@ public class TestLists {
         ));
     }
 
-    public static <T> T serializeAndDeserialize(T t) {
+    public static <T> T serializeAndDeserialize(T t) throws ClassNotFoundException {
         Output output = new Output(1000, -1);
+        kryo.register(Class.forName("java.util.List"));
         kryo.writeClassAndObject(output, t);
         Input input = new Input(output.toBytes());
         return (T) kryo.readClassAndObject(input);
diff --git a/chill-java/src/test/scala/com/twitter/chill/config/ConfiguredInstantiatorTest.scala b/chill-java/src/test/scala/com/twitter/chill/config/ConfiguredInstantiatorTest.scala
index ae4e3a19..6d2a4af3 100644
--- a/chill-java/src/test/scala/com/twitter/chill/config/ConfiguredInstantiatorTest.scala
+++ b/chill-java/src/test/scala/com/twitter/chill/config/ConfiguredInstantiatorTest.scala
@@ -20,13 +20,21 @@ import org.scalacheck.Prop.forAll
 import org.scalacheck.Properties
 
 import com.twitter.chill._
-import com.esotericsoftware.kryo.Kryo
+import com.esotericsoftware.kryo.kryo5.Kryo
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpec
 
 class TestInst extends KryoInstantiator { override def newKryo = new Kryo }
 class TestInstTwo extends KryoInstantiator { override def newKryo = new Kryo }
 
+class DefaultKryoInstantiator extends KryoInstantiator {
+  override def newKryo: Kryo = {
+    val k = new Kryo
+    k.setRegistrationRequired(false)
+    k
+  }
+}
+
 class ReflectingInstantiatorTest extends AnyWordSpec with Matchers {
   "A ConfiguredInstantiator" should {
     "work with a reflected instantiator" in {
@@ -38,7 +46,7 @@ class ReflectingInstantiatorTest extends AnyWordSpec with Matchers {
     }
     "work with a serialized instantiator" in {
       val conf = new JavaMapConfig
-      ConfiguredInstantiator.setSerialized(conf, new TestInst)
+      ConfiguredInstantiator.setSerialized(conf, classOf[DefaultKryoInstantiator], new TestInst)
       val cci = new ConfiguredInstantiator(conf)
       // Here is the only assert:
       cci.getDelegate.getClass should equal(classOf[TestInst])
@@ -46,7 +54,7 @@ class ReflectingInstantiatorTest extends AnyWordSpec with Matchers {
       val cci2 = new ConfiguredInstantiator(conf)
       cci.getDelegate should equal(cci2.getDelegate)
       // Set a new serialized and verify caching is still correct:
-      ConfiguredInstantiator.setSerialized(conf, new TestInstTwo)
+      ConfiguredInstantiator.setSerialized(conf, classOf[DefaultKryoInstantiator], new TestInstTwo)
       val cci3 = new ConfiguredInstantiator(conf)
       cci3.getDelegate.getClass should equal(classOf[TestInstTwo])
       (cci3.getDelegate should not).equal(cci2.getDelegate)
diff --git a/chill-java/src/test/scala/com/twitter/chill/java/BitSetTest.scala b/chill-java/src/test/scala/com/twitter/chill/java/BitSetTest.scala
index 043f577f..a50505ec 100644
--- a/chill-java/src/test/scala/com/twitter/chill/java/BitSetTest.scala
+++ b/chill-java/src/test/scala/com/twitter/chill/java/BitSetTest.scala
@@ -2,9 +2,9 @@ package com.twitter.chill.java
 
 import java.util
 
-import com.esotericsoftware.kryo.Kryo
-import com.esotericsoftware.kryo.io.{Input, Output}
-import org.objenesis.strategy.StdInstantiatorStrategy
+import com.esotericsoftware.kryo.kryo5.Kryo
+import com.esotericsoftware.kryo.kryo5.io.{Input, Output}
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy
 
 import scala.util.Random
 import org.scalatest.matchers.must.Matchers
diff --git a/chill-java/src/test/scala/com/twitter/chill/java/LocaleTest.scala b/chill-java/src/test/scala/com/twitter/chill/java/LocaleTest.scala
index c83f81b8..3b3d43ee 100644
--- a/chill-java/src/test/scala/com/twitter/chill/java/LocaleTest.scala
+++ b/chill-java/src/test/scala/com/twitter/chill/java/LocaleTest.scala
@@ -16,11 +16,10 @@ limitations under the License.
 
 package com.twitter.chill.java
 
-import com.esotericsoftware.kryo.Kryo
-import com.esotericsoftware.kryo.io.Input
-import com.esotericsoftware.kryo.io.Output
-
-import org.objenesis.strategy.StdInstantiatorStrategy
+import com.esotericsoftware.kryo.kryo5.Kryo
+import com.esotericsoftware.kryo.kryo5.io.Input
+import com.esotericsoftware.kryo.kryo5.io.Output
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy
 
 import _root_.java.util.Locale
 import org.scalatest.matchers.should.Matchers
diff --git a/chill-java/src/test/scala/com/twitter/chill/java/OldBitSetSerializer.java b/chill-java/src/test/scala/com/twitter/chill/java/OldBitSetSerializer.java
index 629fc21f..63dec00e 100644
--- a/chill-java/src/test/scala/com/twitter/chill/java/OldBitSetSerializer.java
+++ b/chill-java/src/test/scala/com/twitter/chill/java/OldBitSetSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.java;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 import com.twitter.chill.IKryoRegistrar;
 import com.twitter.chill.SingleRegistrar;
 
@@ -43,7 +43,7 @@ public void write(Kryo kryo, Output output, BitSet bitSet) {
     }
 
     @Override
-    public BitSet read(Kryo kryo, Input input, Class<BitSet> bitSetClass) {
+    public BitSet read(Kryo kryo, Input input, Class<? extends BitSet> bitSetClass) {
         int len = input.readInt(true);
         BitSet ret = new BitSet(len);
 
diff --git a/chill-java/src/test/scala/com/twitter/chill/java/PriorityQueueTest.scala b/chill-java/src/test/scala/com/twitter/chill/java/PriorityQueueTest.scala
index b15f375b..9d2ab24c 100644
--- a/chill-java/src/test/scala/com/twitter/chill/java/PriorityQueueTest.scala
+++ b/chill-java/src/test/scala/com/twitter/chill/java/PriorityQueueTest.scala
@@ -16,15 +16,15 @@ limitations under the License.
 
 package com.twitter.chill.java
 
-import com.esotericsoftware.kryo.Kryo
-import com.esotericsoftware.kryo.io.Input
-import com.esotericsoftware.kryo.io.Output
-
-import org.objenesis.strategy.StdInstantiatorStrategy
+import com.esotericsoftware.kryo.kryo5.Kryo
+import com.esotericsoftware.kryo.kryo5.io.Input
+import com.esotericsoftware.kryo.kryo5.io.Output
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy
+import com.esotericsoftware.kryo.kryo5.serializers.FieldSerializer.FieldSerializerConfig
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpec
 
-class PriorityQueueSpec extends AnyWordSpec with Matchers {
+class PriorityQueueTest extends AnyWordSpec with Matchers {
   def rt[A](k: Kryo, a: A): A = {
     val out = new Output(1000, -1)
     k.writeClassAndObject(out, a.asInstanceOf[AnyRef])
@@ -37,6 +37,22 @@ class PriorityQueueSpec extends AnyWordSpec with Matchers {
       import scala.collection.JavaConverters._
 
       val kryo = new Kryo()
+
+      if (util.Properties.versionString.matches("""^version 2.11.\d+$""")) {
+        kryo.register(Class.forName("scala.math.Ordering$$anon$9"))
+        kryo.register(
+          Class.forName(
+            "com.twitter.chill.java.PriorityQueueTest$$anonfun$1$$anonfun$apply$mcV$sp$1$$anonfun$2"
+          )
+        )
+      }
+
+      if (util.Properties.versionString.matches("""^version 2.1[2-3].\d+$""")) {
+        kryo.register(Class.forName("scala.math.Ordering$$anon$4"))
+        kryo.register(Class.forName("com.twitter.chill.java.PriorityQueueTest"))
+      }
+
+      kryo.register(Class.forName("scala.Tuple2$mcII$sp"))
       kryo.setInstantiatorStrategy(new StdInstantiatorStrategy)
       PriorityQueueSerializer.registrar()(kryo)
       new Java8ClosureRegistrar()(kryo)
@@ -60,8 +76,10 @@ class PriorityQueueSpec extends AnyWordSpec with Matchers {
       // Now with a reverse ordering
       // Note that in chill-scala, synthetic fields are not ignored by default
       // using the ScalaKryoInstantiator
-      val synthF = new com.esotericsoftware.kryo.serializers.FieldSerializer(kryo, ord.reverse.getClass)
-      synthF.setIgnoreSyntheticFields(false)
+      val fsConfig = new FieldSerializerConfig()
+      fsConfig.setIgnoreSyntheticFields(false)
+      val synthF =
+        new com.esotericsoftware.kryo.kryo5.serializers.FieldSerializer(kryo, ord.reverse.getClass, fsConfig)
       kryo.register(ord.reverse.getClass, synthF)
       val qr = new java.util.PriorityQueue[(Int, Int)](3, ord.reverse)
       qr.add((2, 3))
diff --git a/chill-protobuf/src/main/java/com/twitter/chill/protobuf/ProtobufSerializer.java b/chill-protobuf/src/main/java/com/twitter/chill/protobuf/ProtobufSerializer.java
index 072a7636..7bc0dfe2 100644
--- a/chill-protobuf/src/main/java/com/twitter/chill/protobuf/ProtobufSerializer.java
+++ b/chill-protobuf/src/main/java/com/twitter/chill/protobuf/ProtobufSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.protobuf;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import com.google.protobuf.Message;
 
@@ -77,7 +77,7 @@ public void write(Kryo kryo, Output output, Message mes) {
   }
 
   @Override
-  public Message read(Kryo kryo, Input input, Class<Message> pbClass) {
+  public Message read(Kryo kryo, Input input, Class<? extends Message> pbClass) {
     try {
       int size = input.readInt(true);
       if (size == 0) {
diff --git a/chill-protobuf/src/test/scala/com/twitter/chill/protobuf/ProtobufTest.scala b/chill-protobuf/src/test/scala/com/twitter/chill/protobuf/ProtobufTest.scala
index 54c9bc28..3c46c04b 100644
--- a/chill-protobuf/src/test/scala/com/twitter/chill/protobuf/ProtobufTest.scala
+++ b/chill-protobuf/src/test/scala/com/twitter/chill/protobuf/ProtobufTest.scala
@@ -16,10 +16,11 @@
 
 package com.twitter.chill.protobuf
 
+import com.twitter.chill.java.UnmodifiableListSerializer
 import com.twitter.chill.{KryoInstantiator, KryoPool}
 import com.twitter.chill.protobuf.TestMessages.FatigueCount
 
-import com.esotericsoftware.kryo.Kryo
+import com.esotericsoftware.kryo.kryo5.Kryo
 
 import com.google.protobuf.Message
 
@@ -34,6 +35,15 @@ class ProtobufTest extends AnyWordSpec with Matchers {
         override def newKryo(): Kryo = {
           val k = new Kryo
           k.addDefaultSerializer(classOf[Message], classOf[ProtobufSerializer])
+          k.register(Class.forName("com.twitter.chill.protobuf.TestMessages$FatigueCount"))
+          k.register(Class.forName("java.util.ArrayList"))
+          k.register(
+            Class.forName("java.util.Collections$UnmodifiableRandomAccessList"),
+            new UnmodifiableListSerializer
+          )
+          k.register(Class.forName("com.google.protobuf.UnknownFieldSet"))
+          k.register(Class.forName("java.util.Collections$EmptyMap"))
+          k.addDefaultSerializer(classOf[Message], classOf[ProtobufSerializer])
           k
         }
       }
diff --git a/chill-scala/src/main/scala-2.12-/com/twitter/chill/ClassManifestSerializer.scala b/chill-scala/src/main/scala-2.12-/com/twitter/chill/ClassManifestSerializer.scala
index 37dcfa0c..1d0b718d 100644
--- a/chill-scala/src/main/scala-2.12-/com/twitter/chill/ClassManifestSerializer.scala
+++ b/chill-scala/src/main/scala-2.12-/com/twitter/chill/ClassManifestSerializer.scala
@@ -20,7 +20,7 @@ class ClassManifestSerializer[T] extends KSerializer[ClassManifest[T]] {
   def write(kser: Kryo, out: Output, obj: ClassManifest[T]): Unit =
     kser.writeObject(out, obj.runtimeClass)
 
-  def read(kser: Kryo, in: Input, cls: Class[ClassManifest[T]]): ClassManifest[T] = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: ClassManifest[T]]): ClassManifest[T] = {
     val clazz = kser.readObject(in, classOf[Class[T]])
     ClassManifest.fromClass[T](clazz)
   }
diff --git a/chill-scala/src/main/scala-2.12-/com/twitter/chill/Traversable.scala b/chill-scala/src/main/scala-2.12-/com/twitter/chill/Traversable.scala
index c4547761..cb4b740a 100644
--- a/chill-scala/src/main/scala-2.12-/com/twitter/chill/Traversable.scala
+++ b/chill-scala/src/main/scala-2.12-/com/twitter/chill/Traversable.scala
@@ -32,7 +32,7 @@ class TraversableSerializer[T, C <: Traversable[T]](override val isImmutable: Bo
     }
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[C]): C = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: C]): C = {
     val size = in.readInt(true)
     // Go ahead and be faster, and not as functional cool, and be mutable in here
     var idx = 0
diff --git a/chill-scala/src/main/scala-2.12-/com/twitter/chill/WrappedArraySerializer.scala b/chill-scala/src/main/scala-2.12-/com/twitter/chill/WrappedArraySerializer.scala
index 54119cce..440ec133 100644
--- a/chill-scala/src/main/scala-2.12-/com/twitter/chill/WrappedArraySerializer.scala
+++ b/chill-scala/src/main/scala-2.12-/com/twitter/chill/WrappedArraySerializer.scala
@@ -28,7 +28,7 @@ class WrappedArraySerializer[T] extends KSerializer[WrappedArray[T]] {
     kser.writeClassAndObject(out, obj.array)
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[WrappedArray[T]]): mutable.WrappedArray[T] = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: WrappedArray[T]]): mutable.WrappedArray[T] = {
     // Write the class-manifest, we don't use writeClass because it
     // uses the registration system, and this class might not be registered
     val clazz = kser.readObject(in, classOf[Class[T]])
diff --git a/chill-scala/src/main/scala-2.13+/com/twitter/chill/Traversable.scala b/chill-scala/src/main/scala-2.13+/com/twitter/chill/Traversable.scala
index 6a25a558..1a89ac7b 100644
--- a/chill-scala/src/main/scala-2.13+/com/twitter/chill/Traversable.scala
+++ b/chill-scala/src/main/scala-2.13+/com/twitter/chill/Traversable.scala
@@ -32,7 +32,7 @@ class TraversableSerializer[T, C <: Iterable[T]](override val isImmutable: Boole
     }
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[C]): C = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: C]): C = {
     val size = in.readInt(true)
     // Go ahead and be faster, and not as functional cool, and be mutable in here
     var idx = 0
diff --git a/chill-scala/src/main/scala-2.13+/com/twitter/chill/WrappedArraySerializer.scala b/chill-scala/src/main/scala-2.13+/com/twitter/chill/WrappedArraySerializer.scala
index d9e23c45..b67cc8bb 100644
--- a/chill-scala/src/main/scala-2.13+/com/twitter/chill/WrappedArraySerializer.scala
+++ b/chill-scala/src/main/scala-2.13+/com/twitter/chill/WrappedArraySerializer.scala
@@ -27,7 +27,7 @@ class WrappedArraySerializer[T] extends KSerializer[ArraySeq[T]] {
     kser.writeClassAndObject(out, obj.array)
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[ArraySeq[T]]): ArraySeq[T] = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: ArraySeq[T]]): ArraySeq[T] = {
     // Write the class-manifest, we don't use writeClass because it
     // uses the registration system, and this class might not be registered
     val clazz = kser.readObject(in, classOf[Class[T]])
diff --git a/chill-scala/src/main/scala/com/twitter/chill/BigDecimalSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/BigDecimalSerializer.scala
index a238ea19..901a187d 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/BigDecimalSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/BigDecimalSerializer.scala
@@ -20,7 +20,7 @@ import _root_.java.math.{BigDecimal => JBigDecimal}
 import _root_.scala.math.BigDecimal
 
 private class BigDecimalSerializer extends KSerializer[BigDecimal] {
-  override def read(kryo: Kryo, input: Input, cls: Class[BigDecimal]): BigDecimal = {
+  override def read(kryo: Kryo, input: Input, cls: Class[_ <: BigDecimal]): BigDecimal = {
     val jBigDec = kryo.readClassAndObject(input).asInstanceOf[JBigDecimal]
     BigDecimal(jBigDec)
   }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/BitSetSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/BitSetSerializer.scala
index 94066127..3146469b 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/BitSetSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/BitSetSerializer.scala
@@ -36,14 +36,14 @@ class BitSetSerializer extends KSerializer[BitSet] {
       previous = vi
     }
   }
-  def read(k: Kryo, i: Input, c: Class[BitSet]): BitSet = {
+  def read(k: Kryo, i: Input, c: Class[_ <: BitSet]): BitSet = {
     val size = i.readInt(true)
     if (size == 0) {
       BitSet.empty
     } else {
       var sum = 0
       val bits = new Array[Long](i.readInt(true) / 64 + 1)
-      (0 until size).foreach { step =>
+      (0 until size).foreach { _ =>
         sum += i.readInt(true)
         bits(sum / 64) |= 1L << (sum % 64)
       }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/ClassTagSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/ClassTagSerializer.scala
index 5c64d4ce..c0a28596 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/ClassTagSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/ClassTagSerializer.scala
@@ -22,7 +22,7 @@ class ClassTagSerializer[T] extends KSerializer[ClassTag[T]] {
   def write(kser: Kryo, out: Output, obj: ClassTag[T]): Unit =
     kser.writeObject(out, obj.runtimeClass)
 
-  def read(kser: Kryo, in: Input, cls: Class[ClassTag[T]]): ClassTag[T] = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: ClassTag[T]]): ClassTag[T] = {
     val clazz = kser.readObject(in, classOf[Class[T]])
     ClassTag(clazz)
   }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/CleaningSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/CleaningSerializer.scala
index 2dd4e061..f593e689 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/CleaningSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/CleaningSerializer.scala
@@ -22,6 +22,6 @@ class CleaningSerializer[T <: AnyRef](wrapped: KSerializer[T]) extends KSerializ
     wrapped.write(kser, out, item)
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[T]): T =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: T]): T =
     wrapped.read(kser, in, cls)
 }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/EitherSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/EitherSerializer.scala
index 07fae478..48b402db 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/EitherSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/EitherSerializer.scala
@@ -20,7 +20,7 @@ class LeftSerializer[A, B] extends KSerializer[Left[A, B]] {
   def write(kser: Kryo, out: Output, left: Left[A, B]): Unit =
     kser.writeClassAndObject(out, left.left.get)
 
-  def read(kser: Kryo, in: Input, cls: Class[Left[A, B]]): Left[A, B] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Left[A, B]]): Left[A, B] =
     Left(kser.readClassAndObject(in).asInstanceOf[A])
 }
 
@@ -28,6 +28,6 @@ class RightSerializer[A, B] extends KSerializer[Right[A, B]] {
   def write(kser: Kryo, out: Output, right: Right[A, B]): Unit =
     kser.writeClassAndObject(out, right.right.get)
 
-  def read(kser: Kryo, in: Input, cls: Class[Right[A, B]]): Right[A, B] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Right[A, B]]): Right[A, B] =
     Right(kser.readClassAndObject(in).asInstanceOf[B])
 }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/EnumerationSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/EnumerationSerializer.scala
index ffb1b1b8..4b487c83 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/EnumerationSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/EnumerationSerializer.scala
@@ -43,7 +43,7 @@ class EnumerationSerializer extends KSerializer[Enumeration#Value] {
     out.writeInt(obj.id)
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[Enumeration#Value]): Enumeration#Value = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Enumeration#Value]): Enumeration#Value = {
     // Note due to the ObjectSerializer, this only really writes the class.
     val enum = kser.readClassAndObject(in).asInstanceOf[Enumeration]
     enum(in.readInt).asInstanceOf[Enumeration#Value]
diff --git a/chill-scala/src/main/scala/com/twitter/chill/Externalizer.scala b/chill-scala/src/main/scala/com/twitter/chill/Externalizer.scala
index 03f2144d..0d9261bb 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/Externalizer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/Externalizer.scala
@@ -26,7 +26,7 @@ import _root_.java.io.{
 }
 
 import _root_.java.util.concurrent.atomic.{AtomicBoolean, AtomicReference}
-import com.esotericsoftware.kryo.KryoSerializable
+import com.esotericsoftware.kryo.kryo5.KryoSerializable
 
 object Externalizer {
   /* Tokens used to distinguish if we used Kryo or Java */
diff --git a/chill-scala/src/main/scala/com/twitter/chill/JavaIterableWrapperSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/JavaIterableWrapperSerializer.scala
index 39aecab2..3f2fc898 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/JavaIterableWrapperSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/JavaIterableWrapperSerializer.scala
@@ -23,7 +23,7 @@ private class JavaIterableWrapperSerializer extends KSerializer[JIterable[_]] {
       kryo.writeClassAndObject(out, obj)
     }
 
-  override def read(kryo: Kryo, in: Input, clz: Class[JIterable[_]]): JIterable[_] =
+  override def read(kryo: Kryo, in: Input, clz: Class[_ <: JIterable[_]]): JIterable[_] =
     kryo.readClassAndObject(in) match {
       case scalaIterable: Iterable[_] =>
         asJavaIterableConverter(scalaIterable).asJava
@@ -41,7 +41,7 @@ private object JavaIterableWrapperSerializer {
   private val underlyingMethodOpt =
     try Some(wrapperClass.getDeclaredMethod("underlying"))
     catch {
-      case e: Exception =>
+      case _: Exception =>
         None
     }
 }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/KryoBase.scala b/chill-scala/src/main/scala/com/twitter/chill/KryoBase.scala
index f177d4cb..b941f474 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/KryoBase.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/KryoBase.scala
@@ -16,18 +16,18 @@ limitations under the License.
 
 package com.twitter.chill
 
-import com.esotericsoftware.kryo.KryoException
-import com.esotericsoftware.reflectasm.ConstructorAccess
-import com.esotericsoftware.kryo.serializers.FieldSerializer
+import com.esotericsoftware.kryo.kryo5.KryoException
+import com.esotericsoftware.kryo.kryo5.reflectasm.ConstructorAccess;
+import com.esotericsoftware.kryo.kryo5.serializers.FieldSerializer
+import com.esotericsoftware.kryo.kryo5.objenesis.instantiator.ObjectInstantiator;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.InstantiatorStrategy;
 
-import org.objenesis.instantiator.ObjectInstantiator
-import org.objenesis.strategy.InstantiatorStrategy
 import _root_.java.lang.reflect.{Constructor, Modifier}
 
-import com.esotericsoftware.kryo.ClassResolver
-import com.esotericsoftware.kryo.ReferenceResolver
-import com.esotericsoftware.kryo.util.DefaultClassResolver
-import com.esotericsoftware.kryo.util.MapReferenceResolver
+import com.esotericsoftware.kryo.kryo5.ClassResolver
+import com.esotericsoftware.kryo.kryo5.ReferenceResolver
+import com.esotericsoftware.kryo.kryo5.util.DefaultClassResolver
+import com.esotericsoftware.kryo.kryo5.util.MapReferenceResolver
 
 import scala.util.{Failure, Success, Try}
 
@@ -83,7 +83,8 @@ class KryoBase(classResolver: ClassResolver, referenceResolver: ReferenceResolve
           // Scala has a lot of synthetic fields that must be serialized:
           // We also enable it by default in java since not wanting these fields
           // serialized looks like the exception rather than the rule.
-          fs.setIgnoreSyntheticFields(false)
+          fs.getFieldSerializerConfig.setIgnoreSyntheticFields(false)
+          fs.updateFields()
 
           /**
            * This breaks scalding, but something like this should be used when working with the repl.
diff --git a/chill-scala/src/main/scala/com/twitter/chill/ManifestSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/ManifestSerializer.scala
index e1c6596c..45ac52e9 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/ManifestSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/ManifestSerializer.scala
@@ -54,7 +54,7 @@ class ManifestSerializer[T] extends KSerializer[Manifest[T]] {
 
   def write(kser: Kryo, out: Output, obj: Manifest[T]): Unit = writeInternal(kser, out, obj)
 
-  def read(kser: Kryo, in: Input, cls: Class[Manifest[T]]): Manifest[T] = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Manifest[T]]): Manifest[T] = {
     val sidx = in.readInt(true)
     if (sidx == 0) {
       val clazz = kser.readObject(in, classOf[Class[T]])
diff --git a/chill-scala/src/main/scala/com/twitter/chill/ObjectSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/ObjectSerializer.scala
index d2a400df..ef9138f4 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/ObjectSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/ObjectSerializer.scala
@@ -35,7 +35,7 @@ class ObjectSerializer[T] extends KSerializer[T] {
   protected def cachedRead(cls: Class[_]): Option[T] =
     cachedObj.synchronized(cachedObj.getOrElseUpdate(cls, createSingleton(cls)))
 
-  override def read(kser: Kryo, in: Input, cls: Class[T]): T = cachedRead(cls).get
+  override def read(kser: Kryo, in: Input, cls: Class[_ <: T]): T = cachedRead(cls).get
 
   def accepts(cls: Class[_]): Boolean = cachedRead(cls).isDefined
 
diff --git a/chill-scala/src/main/scala/com/twitter/chill/RegexSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/RegexSerializer.scala
index b55aeed0..73818938 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/RegexSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/RegexSerializer.scala
@@ -22,6 +22,6 @@ class RegexSerializer extends KSerializer[Regex] {
   def write(kser: Kryo, out: Output, obj: Regex): Unit =
     out.writeString(obj.pattern.pattern)
 
-  def read(kser: Kryo, in: Input, cls: Class[Regex]): Regex =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Regex]): Regex =
     new Regex(in.readString)
 }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/RichKryo.scala b/chill-scala/src/main/scala/com/twitter/chill/RichKryo.scala
index 322110ea..5a24b3a3 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/RichKryo.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/RichKryo.scala
@@ -16,7 +16,7 @@ limitations under the License.
 
 package com.twitter.chill
 
-import com.esotericsoftware.kryo.io.ByteBufferInputStream
+import com.esotericsoftware.kryo.kryo5.io.ByteBufferInputStream
 
 import _root_.java.io.{InputStream, Serializable}
 import _root_.java.nio.ByteBuffer
@@ -50,7 +50,7 @@ class RichKryo(val k: Kryo) extends RichKryoCompat {
    * probably fine
    */
   def javaForClass[T <: Serializable](implicit cmf: ClassTag[T]): Kryo = {
-    k.register(cmf.runtimeClass, new com.esotericsoftware.kryo.serializers.JavaSerializer)
+    k.register(cmf.runtimeClass, new com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer)
     k
   }
 
@@ -59,7 +59,7 @@ class RichKryo(val k: Kryo) extends RichKryoCompat {
    * probably fine
    */
   def javaForSubclass[T <: Serializable](implicit cmf: ClassTag[T]): Kryo = {
-    k.addDefaultSerializer(cmf.runtimeClass, new com.esotericsoftware.kryo.serializers.JavaSerializer)
+    k.addDefaultSerializer(cmf.runtimeClass, new com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer)
     k
   }
 
diff --git a/chill-scala/src/main/scala/com/twitter/chill/ScalaKryoInstantiator.scala b/chill-scala/src/main/scala/com/twitter/chill/ScalaKryoInstantiator.scala
index 8577153e..a7963795 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/ScalaKryoInstantiator.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/ScalaKryoInstantiator.scala
@@ -43,10 +43,11 @@ import scala.collection.mutable.{
   WrappedArray
 }
 import scala.util.matching.Regex
-
 import com.twitter.chill.java.{Java8ClosureRegistrar, PackageRegistrar}
 import _root_.java.io.Serializable
 
+import com.esotericsoftware.kryo.kryo5.serializers.FieldSerializer
+
 import scala.collection.JavaConverters._
 import scala.collection.mutable
 import scala.reflect.ClassTag
@@ -59,7 +60,7 @@ class EmptyScalaKryoInstantiator extends KryoInstantiator {
   override def newKryo: KryoBase = {
     val k = new KryoBase
     k.setRegistrationRequired(false)
-    k.setInstantiatorStrategy(new org.objenesis.strategy.StdInstantiatorStrategy)
+    k.setInstantiatorStrategy(new com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy)
 
     // Handle cases where we may have an odd classloader setup like with libjars
     // for hadoop
@@ -110,8 +111,9 @@ class ScalaCollectionsRegistrar extends IKryoRegistrar {
   def apply(newK: Kryo): Unit = {
     // for binary compat this is here, but could be moved to RichKryo
     def useField[T](cls: Class[T]): Unit = {
-      val fs = new com.esotericsoftware.kryo.serializers.FieldSerializer(newK, cls)
-      fs.setIgnoreSyntheticFields(false) // scala generates a lot of these attributes
+      val fsConfig = new FieldSerializer.FieldSerializerConfig
+      fsConfig.setIgnoreSyntheticFields(false) // scala generates a lot of these attributes
+      val fs = new com.esotericsoftware.kryo.kryo5.serializers.FieldSerializer(newK, cls, fsConfig)
       newK.register(cls, fs)
     }
     // The wrappers are private classes:
@@ -196,7 +198,7 @@ final private[chill] class AllScalaRegistrar_0_9_2 extends IKryoRegistrar {
     k.forClass[Symbol](new KSerializer[Symbol] {
       override def isImmutable = true
       def write(k: Kryo, out: Output, obj: Symbol): Unit = out.writeString(obj.name)
-      def read(k: Kryo, in: Input, cls: Class[Symbol]): Symbol = Symbol(in.readString)
+      def read(k: Kryo, in: Input, cls: Class[_ <: Symbol]): Symbol = Symbol(in.readString)
     }).forSubclass[Regex](new RegexSerializer)
       .forClass[ClassTag[Any]](new ClassTagSerializer[Any])
       .forSubclass[Manifest[Any]](new ManifestSerializer[Any])
diff --git a/chill-scala/src/main/scala/com/twitter/chill/SingletonSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/SingletonSerializer.scala
index c06f2488..16ff1c2a 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/SingletonSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/SingletonSerializer.scala
@@ -21,5 +21,5 @@ package com.twitter.chill
 
 class SingletonSerializer[T](obj: T) extends KSerializer[T] {
   def write(kser: Kryo, out: Output, obj: T): Unit = {}
-  def read(kser: Kryo, in: Input, cls: Class[T]): T = obj
+  def read(kser: Kryo, in: Input, cls: Class[_ <: T]): T = obj
 }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/SomeSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/SomeSerializer.scala
index b81cc799..b428dff0 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/SomeSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/SomeSerializer.scala
@@ -20,6 +20,6 @@ class SomeSerializer[T] extends KSerializer[Some[T]] {
   def write(kser: Kryo, out: Output, item: Some[T]): Unit =
     kser.writeClassAndObject(out, item.get)
 
-  def read(kser: Kryo, in: Input, cls: Class[Some[T]]): Some[T] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Some[T]]): Some[T] =
     Some(kser.readClassAndObject(in).asInstanceOf[T])
 }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/SortedMapSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/SortedMapSerializer.scala
index 7d07c28b..259f7395 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/SortedMapSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/SortedMapSerializer.scala
@@ -35,7 +35,7 @@ class SortedMapSerializer[A, B] extends KSerializer[SortedMap[A, B]] {
     }
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[M]): M = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: M]): M = {
     val size = in.readInt(true)
     val ordering = kser.readClassAndObject(in).asInstanceOf[Ordering[A]]
 
diff --git a/chill-scala/src/main/scala/com/twitter/chill/SortedSetSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/SortedSetSerializer.scala
index 45b7a8aa..37907c01 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/SortedSetSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/SortedSetSerializer.scala
@@ -33,7 +33,7 @@ class SortedSetSerializer[T] extends KSerializer[SortedSet[T]] {
     }
   }
 
-  def read(kser: Kryo, in: Input, cls: Class[SortedSet[T]]): SortedSet[T] = {
+  def read(kser: Kryo, in: Input, cls: Class[_ <: SortedSet[T]]): SortedSet[T] = {
     val size = in.readInt(true)
     val ordering = kser.readClassAndObject(in).asInstanceOf[Ordering[T]]
 
diff --git a/chill-scala/src/main/scala/com/twitter/chill/StreamSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/StreamSerializer.scala
index a243f9a9..e547dfe8 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/StreamSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/StreamSerializer.scala
@@ -4,6 +4,6 @@ class StreamSerializer[T]() extends KSerializer[Stream[T]] {
   def write(kser: Kryo, out: Output, stream: Stream[T]): Unit =
     kser.writeClassAndObject(out, stream.toList)
 
-  def read(kser: Kryo, in: Input, cls: Class[Stream[T]]): Stream[T] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Stream[T]]): Stream[T] =
     kser.readClassAndObject(in).asInstanceOf[List[T]].toStream
 }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/TupleSerializers.scala b/chill-scala/src/main/scala/com/twitter/chill/TupleSerializers.scala
index 5376184d..1f83e95f 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/TupleSerializers.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/TupleSerializers.scala
@@ -25,7 +25,7 @@ class Tuple1Serializer[A] extends KSerializer[Tuple1[A]] with Serializable {
   def write(kser: Kryo, out: Output, obj: Tuple1[A]): Unit = {
     kser.writeClassAndObject(out, obj._1); out.flush;
   }
-  def read(kser: Kryo, in: Input, cls: Class[Tuple1[A]]): Tuple1[A] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple1[A]]): Tuple1[A] =
     new Tuple1[A](
       kser.readClassAndObject(in).asInstanceOf[A]
     )
@@ -36,7 +36,7 @@ class Tuple2Serializer[A, B] extends KSerializer[Tuple2[A, B]] with Serializable
     kser.writeClassAndObject(out, obj._1); out.flush;
     kser.writeClassAndObject(out, obj._2); out.flush;
   }
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[A, B]]): Tuple2[A, B] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[A, B]]): Tuple2[A, B] =
     new Tuple2[A, B](
       kser.readClassAndObject(in).asInstanceOf[A],
       kser.readClassAndObject(in).asInstanceOf[B]
@@ -49,7 +49,7 @@ class Tuple3Serializer[A, B, C] extends KSerializer[Tuple3[A, B, C]] with Serial
     kser.writeClassAndObject(out, obj._2); out.flush;
     kser.writeClassAndObject(out, obj._3); out.flush;
   }
-  def read(kser: Kryo, in: Input, cls: Class[Tuple3[A, B, C]]): Tuple3[A, B, C] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple3[A, B, C]]): Tuple3[A, B, C] =
     new Tuple3[A, B, C](
       kser.readClassAndObject(in).asInstanceOf[A],
       kser.readClassAndObject(in).asInstanceOf[B],
@@ -64,7 +64,7 @@ class Tuple4Serializer[A, B, C, D] extends KSerializer[Tuple4[A, B, C, D]] with
     kser.writeClassAndObject(out, obj._3); out.flush;
     kser.writeClassAndObject(out, obj._4); out.flush;
   }
-  def read(kser: Kryo, in: Input, cls: Class[Tuple4[A, B, C, D]]): Tuple4[A, B, C, D] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple4[A, B, C, D]]): Tuple4[A, B, C, D] =
     new Tuple4[A, B, C, D](
       kser.readClassAndObject(in).asInstanceOf[A],
       kser.readClassAndObject(in).asInstanceOf[B],
@@ -81,7 +81,7 @@ class Tuple5Serializer[A, B, C, D, E] extends KSerializer[Tuple5[A, B, C, D, E]]
     kser.writeClassAndObject(out, obj._4); out.flush;
     kser.writeClassAndObject(out, obj._5); out.flush;
   }
-  def read(kser: Kryo, in: Input, cls: Class[Tuple5[A, B, C, D, E]]): Tuple5[A, B, C, D, E] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple5[A, B, C, D, E]]): Tuple5[A, B, C, D, E] =
     new Tuple5[A, B, C, D, E](
       kser.readClassAndObject(in).asInstanceOf[A],
       kser.readClassAndObject(in).asInstanceOf[B],
@@ -100,7 +100,7 @@ class Tuple6Serializer[A, B, C, D, E, F] extends KSerializer[Tuple6[A, B, C, D,
     kser.writeClassAndObject(out, obj._5); out.flush;
     kser.writeClassAndObject(out, obj._6); out.flush;
   }
-  def read(kser: Kryo, in: Input, cls: Class[Tuple6[A, B, C, D, E, F]]): Tuple6[A, B, C, D, E, F] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple6[A, B, C, D, E, F]]): Tuple6[A, B, C, D, E, F] =
     new Tuple6[A, B, C, D, E, F](
       kser.readClassAndObject(in).asInstanceOf[A],
       kser.readClassAndObject(in).asInstanceOf[B],
@@ -123,7 +123,7 @@ class Tuple7Serializer[A, B, C, D, E, F, G]
     kser.writeClassAndObject(out, obj._6); out.flush;
     kser.writeClassAndObject(out, obj._7); out.flush;
   }
-  def read(kser: Kryo, in: Input, cls: Class[Tuple7[A, B, C, D, E, F, G]]): Tuple7[A, B, C, D, E, F, G] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple7[A, B, C, D, E, F, G]]): Tuple7[A, B, C, D, E, F, G] =
     new Tuple7[A, B, C, D, E, F, G](
       kser.readClassAndObject(in).asInstanceOf[A],
       kser.readClassAndObject(in).asInstanceOf[B],
@@ -151,7 +151,7 @@ class Tuple8Serializer[A, B, C, D, E, F, G, H]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple8[A, B, C, D, E, F, G, H]]
+      cls: Class[_ <: Tuple8[A, B, C, D, E, F, G, H]]
   ): Tuple8[A, B, C, D, E, F, G, H] =
     new Tuple8[A, B, C, D, E, F, G, H](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -182,7 +182,7 @@ class Tuple9Serializer[A, B, C, D, E, F, G, H, I]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple9[A, B, C, D, E, F, G, H, I]]
+      cls: Class[_ <: Tuple9[A, B, C, D, E, F, G, H, I]]
   ): Tuple9[A, B, C, D, E, F, G, H, I] =
     new Tuple9[A, B, C, D, E, F, G, H, I](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -215,7 +215,7 @@ class Tuple10Serializer[A, B, C, D, E, F, G, H, I, J]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple10[A, B, C, D, E, F, G, H, I, J]]
+      cls: Class[_ <: Tuple10[A, B, C, D, E, F, G, H, I, J]]
   ): Tuple10[A, B, C, D, E, F, G, H, I, J] =
     new Tuple10[A, B, C, D, E, F, G, H, I, J](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -250,7 +250,7 @@ class Tuple11Serializer[A, B, C, D, E, F, G, H, I, J, K]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple11[A, B, C, D, E, F, G, H, I, J, K]]
+      cls: Class[_ <: Tuple11[A, B, C, D, E, F, G, H, I, J, K]]
   ): Tuple11[A, B, C, D, E, F, G, H, I, J, K] =
     new Tuple11[A, B, C, D, E, F, G, H, I, J, K](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -287,7 +287,7 @@ class Tuple12Serializer[A, B, C, D, E, F, G, H, I, J, K, L]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple12[A, B, C, D, E, F, G, H, I, J, K, L]]
+      cls: Class[_ <: Tuple12[A, B, C, D, E, F, G, H, I, J, K, L]]
   ): Tuple12[A, B, C, D, E, F, G, H, I, J, K, L] =
     new Tuple12[A, B, C, D, E, F, G, H, I, J, K, L](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -326,7 +326,7 @@ class Tuple13Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple13[A, B, C, D, E, F, G, H, I, J, K, L, M]]
+      cls: Class[_ <: Tuple13[A, B, C, D, E, F, G, H, I, J, K, L, M]]
   ): Tuple13[A, B, C, D, E, F, G, H, I, J, K, L, M] =
     new Tuple13[A, B, C, D, E, F, G, H, I, J, K, L, M](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -367,7 +367,7 @@ class Tuple14Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple14[A, B, C, D, E, F, G, H, I, J, K, L, M, N]]
+      cls: Class[_ <: Tuple14[A, B, C, D, E, F, G, H, I, J, K, L, M, N]]
   ): Tuple14[A, B, C, D, E, F, G, H, I, J, K, L, M, N] =
     new Tuple14[A, B, C, D, E, F, G, H, I, J, K, L, M, N](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -410,7 +410,7 @@ class Tuple15Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple15[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O]]
+      cls: Class[_ <: Tuple15[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O]]
   ): Tuple15[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O] =
     new Tuple15[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -455,7 +455,7 @@ class Tuple16Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple16[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P]]
+      cls: Class[_ <: Tuple16[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P]]
   ): Tuple16[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P] =
     new Tuple16[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -506,7 +506,7 @@ class Tuple17Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple17[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q]]
+      cls: Class[_ <: Tuple17[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q]]
   ): Tuple17[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q] =
     new Tuple17[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -559,7 +559,7 @@ class Tuple18Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple18[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R]]
+      cls: Class[_ <: Tuple18[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R]]
   ): Tuple18[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R] =
     new Tuple18[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -614,7 +614,7 @@ class Tuple19Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S]
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple19[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S]]
+      cls: Class[_ <: Tuple19[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S]]
   ): Tuple19[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S] =
     new Tuple19[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -671,7 +671,7 @@ class Tuple20Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S,
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple20[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T]]
+      cls: Class[_ <: Tuple20[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T]]
   ): Tuple20[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T] =
     new Tuple20[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -730,7 +730,7 @@ class Tuple21Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S,
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple21[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U]]
+      cls: Class[_ <: Tuple21[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U]]
   ): Tuple21[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U] =
     new Tuple21[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -791,7 +791,7 @@ class Tuple22Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S,
   def read(
       kser: Kryo,
       in: Input,
-      cls: Class[Tuple22[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V]]
+      cls: Class[_ <: Tuple22[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V]]
   ): Tuple22[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V] =
     new Tuple22[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V](
       kser.readClassAndObject(in).asInstanceOf[A],
@@ -821,7 +821,7 @@ class Tuple22Serializer[A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S,
 
 class Tuple1LongSerializer extends KSerializer[Tuple1[Long]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple1[Long]]): Tuple1[Long] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple1[Long]]): Tuple1[Long] =
     new Tuple1[Long](in.readLong)
   def write(kser: Kryo, out: Output, tup: Tuple1[Long]): Unit =
     out.writeLong(tup._1)
@@ -829,7 +829,7 @@ class Tuple1LongSerializer extends KSerializer[Tuple1[Long]] with Serializable {
 
 class Tuple1IntSerializer extends KSerializer[Tuple1[Int]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple1[Int]]): Tuple1[Int] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple1[Int]]): Tuple1[Int] =
     new Tuple1[Int](in.readInt)
   def write(kser: Kryo, out: Output, tup: Tuple1[Int]): Unit =
     out.writeInt(tup._1)
@@ -837,7 +837,7 @@ class Tuple1IntSerializer extends KSerializer[Tuple1[Int]] with Serializable {
 
 class Tuple1DoubleSerializer extends KSerializer[Tuple1[Double]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple1[Double]]): Tuple1[Double] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple1[Double]]): Tuple1[Double] =
     new Tuple1[Double](in.readDouble)
   def write(kser: Kryo, out: Output, tup: Tuple1[Double]): Unit =
     out.writeDouble(tup._1)
@@ -845,7 +845,7 @@ class Tuple1DoubleSerializer extends KSerializer[Tuple1[Double]] with Serializab
 
 class Tuple2LongLongSerializer extends KSerializer[Tuple2[Long, Long]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Long, Long]]): Tuple2[Long, Long] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Long, Long]]): Tuple2[Long, Long] =
     new Tuple2[Long, Long](in.readLong, in.readLong)
   def write(kser: Kryo, out: Output, tup: Tuple2[Long, Long]): Unit = {
     out.writeLong(tup._1)
@@ -855,7 +855,7 @@ class Tuple2LongLongSerializer extends KSerializer[Tuple2[Long, Long]] with Seri
 
 class Tuple2LongIntSerializer extends KSerializer[Tuple2[Long, Int]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Long, Int]]): Tuple2[Long, Int] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Long, Int]]): Tuple2[Long, Int] =
     new Tuple2[Long, Int](in.readLong, in.readInt)
   def write(kser: Kryo, out: Output, tup: Tuple2[Long, Int]): Unit = {
     out.writeLong(tup._1)
@@ -865,7 +865,7 @@ class Tuple2LongIntSerializer extends KSerializer[Tuple2[Long, Int]] with Serial
 
 class Tuple2LongDoubleSerializer extends KSerializer[Tuple2[Long, Double]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Long, Double]]): Tuple2[Long, Double] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Long, Double]]): Tuple2[Long, Double] =
     new Tuple2[Long, Double](in.readLong, in.readDouble)
   def write(kser: Kryo, out: Output, tup: Tuple2[Long, Double]): Unit = {
     out.writeLong(tup._1)
@@ -875,7 +875,7 @@ class Tuple2LongDoubleSerializer extends KSerializer[Tuple2[Long, Double]] with
 
 class Tuple2IntLongSerializer extends KSerializer[Tuple2[Int, Long]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Int, Long]]): Tuple2[Int, Long] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Int, Long]]): Tuple2[Int, Long] =
     new Tuple2[Int, Long](in.readInt, in.readLong)
   def write(kser: Kryo, out: Output, tup: Tuple2[Int, Long]): Unit = {
     out.writeInt(tup._1)
@@ -885,7 +885,7 @@ class Tuple2IntLongSerializer extends KSerializer[Tuple2[Int, Long]] with Serial
 
 class Tuple2IntIntSerializer extends KSerializer[Tuple2[Int, Int]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Int, Int]]): Tuple2[Int, Int] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Int, Int]]): Tuple2[Int, Int] =
     new Tuple2[Int, Int](in.readInt, in.readInt)
   def write(kser: Kryo, out: Output, tup: Tuple2[Int, Int]): Unit = {
     out.writeInt(tup._1)
@@ -895,7 +895,7 @@ class Tuple2IntIntSerializer extends KSerializer[Tuple2[Int, Int]] with Serializ
 
 class Tuple2IntDoubleSerializer extends KSerializer[Tuple2[Int, Double]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Int, Double]]): Tuple2[Int, Double] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Int, Double]]): Tuple2[Int, Double] =
     new Tuple2[Int, Double](in.readInt, in.readDouble)
   def write(kser: Kryo, out: Output, tup: Tuple2[Int, Double]): Unit = {
     out.writeInt(tup._1)
@@ -905,7 +905,7 @@ class Tuple2IntDoubleSerializer extends KSerializer[Tuple2[Int, Double]] with Se
 
 class Tuple2DoubleLongSerializer extends KSerializer[Tuple2[Double, Long]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Double, Long]]): Tuple2[Double, Long] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Double, Long]]): Tuple2[Double, Long] =
     new Tuple2[Double, Long](in.readDouble, in.readLong)
   def write(kser: Kryo, out: Output, tup: Tuple2[Double, Long]): Unit = {
     out.writeDouble(tup._1)
@@ -915,7 +915,7 @@ class Tuple2DoubleLongSerializer extends KSerializer[Tuple2[Double, Long]] with
 
 class Tuple2DoubleIntSerializer extends KSerializer[Tuple2[Double, Int]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Double, Int]]): Tuple2[Double, Int] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Double, Int]]): Tuple2[Double, Int] =
     new Tuple2[Double, Int](in.readDouble, in.readInt)
   def write(kser: Kryo, out: Output, tup: Tuple2[Double, Int]): Unit = {
     out.writeDouble(tup._1)
@@ -925,7 +925,7 @@ class Tuple2DoubleIntSerializer extends KSerializer[Tuple2[Double, Int]] with Se
 
 class Tuple2DoubleDoubleSerializer extends KSerializer[Tuple2[Double, Double]] with Serializable {
   setImmutable(true)
-  def read(kser: Kryo, in: Input, cls: Class[Tuple2[Double, Double]]): Tuple2[Double, Double] =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: Tuple2[Double, Double]]): Tuple2[Double, Double] =
     new Tuple2[Double, Double](in.readDouble, in.readDouble)
   def write(kser: Kryo, out: Output, tup: Tuple2[Double, Double]): Unit = {
     out.writeDouble(tup._1)
diff --git a/chill-scala/src/main/scala/com/twitter/chill/VolatileByteRefSerializer.scala b/chill-scala/src/main/scala/com/twitter/chill/VolatileByteRefSerializer.scala
index e160a3ae..8f5fcf1c 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/VolatileByteRefSerializer.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/VolatileByteRefSerializer.scala
@@ -6,6 +6,6 @@ class VolatileByteRefSerializer extends KSerializer[VolatileByteRef] {
   def write(kser: Kryo, out: Output, item: VolatileByteRef): Unit =
     out.writeByte(item.elem)
 
-  def read(kser: Kryo, in: Input, cls: Class[VolatileByteRef]) =
+  def read(kser: Kryo, in: Input, cls: Class[_ <: VolatileByteRef]) =
     new VolatileByteRef(in.readByte)
 }
diff --git a/chill-scala/src/main/scala/com/twitter/chill/config/ReflectingInstantiatorBuilder.scala b/chill-scala/src/main/scala/com/twitter/chill/config/ReflectingInstantiatorBuilder.scala
index 1833233f..47e115c6 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/config/ReflectingInstantiatorBuilder.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/config/ReflectingInstantiatorBuilder.scala
@@ -18,9 +18,9 @@ package com.twitter.chill.config
 
 import com.twitter.chill._
 
-import com.esotericsoftware.kryo.Kryo;
-import org.objenesis.strategy.InstantiatorStrategy;
-import org.objenesis.strategy.StdInstantiatorStrategy;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.InstantiatorStrategy;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy;
 
 import scala.collection.JavaConverters._
 
diff --git a/chill-scala/src/main/scala/com/twitter/chill/config/ScalaAnyRefMapConfig.scala b/chill-scala/src/main/scala/com/twitter/chill/config/ScalaAnyRefMapConfig.scala
index c1ef1160..27fb7113 100644
--- a/chill-scala/src/main/scala/com/twitter/chill/config/ScalaAnyRefMapConfig.scala
+++ b/chill-scala/src/main/scala/com/twitter/chill/config/ScalaAnyRefMapConfig.scala
@@ -34,7 +34,7 @@ class ScalaAnyRefMapConfig(in: Map[AnyRef, AnyRef]) extends Config {
   override def get(k: String): String = conf.get(k).map(_.toString).getOrElse(null)
   override def set(k: String, v: String): Unit =
     Option(v) match {
-      case Some(r) => conf += k -> v
+      case Some(_) => conf += k -> v
       case None    => conf -= k
     }
 }
diff --git a/chill-scala/src/main/scala/com/twitter/package.scala b/chill-scala/src/main/scala/com/twitter/package.scala
index b827114a..a3bfa9de 100644
--- a/chill-scala/src/main/scala/com/twitter/package.scala
+++ b/chill-scala/src/main/scala/com/twitter/package.scala
@@ -20,10 +20,10 @@ package com.twitter
  * Scala extensions to the Kryo serialization library.
  */
 package object chill {
-  type Kryo = com.esotericsoftware.kryo.Kryo
-  type KSerializer[T] = com.esotericsoftware.kryo.Serializer[T]
-  type Input = com.esotericsoftware.kryo.io.Input
-  type Output = com.esotericsoftware.kryo.io.Output
+  type Kryo = com.esotericsoftware.kryo.kryo5.Kryo
+  type KSerializer[T] = com.esotericsoftware.kryo.kryo5.Serializer[T]
+  type Input = com.esotericsoftware.kryo.kryo5.io.Input
+  type Output = com.esotericsoftware.kryo.kryo5.io.Output
 
   implicit def toRich(k: Kryo): RichKryo = new RichKryo(k)
   implicit def toInstantiator(fn: Function0[Kryo]): KryoInstantiator = new KryoInstantiator {
diff --git a/chill-scala/src/test/scala-2.12-/com/twitter/chill/RegistrationIdsSpecData.scala b/chill-scala/src/test/scala-2.12-/com/twitter/chill/RegistrationIdsSpecData.scala
index d7c5e8ee..44ce35fa 100644
--- a/chill-scala/src/test/scala-2.12-/com/twitter/chill/RegistrationIdsSpecData.scala
+++ b/chill-scala/src/test/scala-2.12-/com/twitter/chill/RegistrationIdsSpecData.scala
@@ -27,146 +27,145 @@ object RegistrationIdsSpecData {
       |6 -> short
       |7 -> long
       |8 -> double
-      |9 -> void
-      |10 -> class scala.collection.convert.Wrappers$SeqWrapper
-      |11 -> class scala.collection.convert.Wrappers$IteratorWrapper
-      |12 -> class scala.collection.convert.Wrappers$MapWrapper
-      |13 -> class scala.collection.convert.Wrappers$JListWrapper
-      |14 -> class scala.collection.convert.Wrappers$JMapWrapper
-      |15 -> class scala.Some
-      |16 -> class scala.util.Left
-      |17 -> class scala.util.Right
-      |18 -> class scala.collection.immutable.Vector
-      |19 -> class scala.collection.immutable.Set$Set1
-      |20 -> class scala.collection.immutable.Set$Set2
-      |21 -> class scala.collection.immutable.Set$Set3
-      |22 -> class scala.collection.immutable.Set$Set4
-      |23 -> class scala.collection.immutable.HashSet$HashTrieSet
-      |24 -> class scala.collection.immutable.Map$Map1
-      |25 -> class scala.collection.immutable.Map$Map2
-      |26 -> class scala.collection.immutable.Map$Map3
-      |27 -> class scala.collection.immutable.Map$Map4
-      |28 -> class scala.collection.immutable.HashMap$HashTrieMap
-      |29 -> class scala.collection.immutable.Range$Inclusive
-      |30 -> class scala.collection.immutable.NumericRange$Inclusive
-      |31 -> class scala.collection.immutable.NumericRange$Exclusive
-      |32 -> class scala.collection.mutable.BitSet
-      |33 -> class scala.collection.mutable.HashMap
-      |34 -> class scala.collection.mutable.HashSet
-      |35 -> class scala.collection.convert.Wrappers$IterableWrapper
-      |36 -> class scala.Tuple1
-      |37 -> class scala.Tuple2
-      |38 -> class scala.Tuple3
-      |39 -> class scala.Tuple4
-      |40 -> class scala.Tuple5
-      |41 -> class scala.Tuple6
-      |42 -> class scala.Tuple7
-      |43 -> class scala.Tuple8
-      |44 -> class scala.Tuple9
-      |45 -> class scala.Tuple10
-      |46 -> class scala.Tuple11
-      |47 -> class scala.Tuple12
-      |48 -> class scala.Tuple13
-      |49 -> class scala.Tuple14
-      |50 -> class scala.Tuple15
-      |51 -> class scala.Tuple16
-      |52 -> class scala.Tuple17
-      |53 -> class scala.Tuple18
-      |54 -> class scala.Tuple19
-      |55 -> class scala.Tuple20
-      |56 -> class scala.Tuple21
-      |57 -> class scala.Tuple22
-      |58 -> class scala.Tuple1$mcJ$sp
-      |59 -> class scala.Tuple1$mcI$sp
-      |60 -> class scala.Tuple1$mcD$sp
-      |61 -> class scala.Tuple2$mcJJ$sp
-      |62 -> class scala.Tuple2$mcJI$sp
-      |63 -> class scala.Tuple2$mcJD$sp
-      |64 -> class scala.Tuple2$mcIJ$sp
-      |65 -> class scala.Tuple2$mcII$sp
-      |66 -> class scala.Tuple2$mcID$sp
-      |67 -> class scala.Tuple2$mcDJ$sp
-      |68 -> class scala.Tuple2$mcDI$sp
-      |69 -> class scala.Tuple2$mcDD$sp
-      |70 -> class scala.Symbol
-      |71 -> interface scala.reflect.ClassTag
-      |72 -> class scala.runtime.BoxedUnit
-      |73 -> class java.util.Arrays$ArrayList
-      |74 -> class java.util.BitSet
-      |75 -> class java.util.PriorityQueue
-      |76 -> class java.util.regex.Pattern
-      |77 -> class java.sql.Date
-      |78 -> class java.sql.Time
-      |79 -> class java.sql.Timestamp
-      |80 -> class java.net.URI
-      |81 -> class java.net.InetSocketAddress
-      |82 -> class java.util.UUID
-      |83 -> class java.util.Locale
-      |84 -> class java.text.SimpleDateFormat
-      |85 -> class java.util.Collections$UnmodifiableCollection
-      |86 -> class java.util.Collections$UnmodifiableRandomAccessList
-      |87 -> class java.util.Collections$UnmodifiableList
-      |88 -> class java.util.Collections$UnmodifiableMap
-      |89 -> class java.util.Collections$UnmodifiableSet
-      |90 -> class java.util.Collections$UnmodifiableSortedMap
-      |91 -> class java.util.Collections$UnmodifiableSortedSet
-      |92 -> class com.esotericsoftware.kryo.serializers.ClosureSerializer$Closure
-      |93 -> class [B
-      |94 -> class [S
-      |95 -> class [I
-      |96 -> class [J
-      |97 -> class [F
-      |98 -> class [D
-      |99 -> class [Z
-      |100 -> class [C
-      |101 -> class [Ljava.lang.String;
-      |102 -> class [Ljava.lang.Object;
-      |103 -> class java.lang.Class
-      |104 -> class java.lang.Object
-      |105 -> class scala.collection.mutable.WrappedArray$ofByte
-      |106 -> class scala.collection.mutable.WrappedArray$ofShort
-      |107 -> class scala.collection.mutable.WrappedArray$ofInt
-      |108 -> class scala.collection.mutable.WrappedArray$ofLong
-      |109 -> class scala.collection.mutable.WrappedArray$ofFloat
-      |110 -> class scala.collection.mutable.WrappedArray$ofDouble
-      |111 -> class scala.collection.mutable.WrappedArray$ofBoolean
-      |112 -> class scala.collection.mutable.WrappedArray$ofChar
-      |113 -> class scala.collection.mutable.WrappedArray$ofRef
-      |114 -> class scala.None$
-      |115 -> class scala.collection.immutable.Queue
-      |116 -> class scala.collection.immutable.Nil$
-      |117 -> class scala.collection.immutable.$colon$colon
-      |118 -> class scala.collection.immutable.Range
-      |119 -> class scala.collection.immutable.WrappedString
-      |120 -> class scala.collection.immutable.TreeSet
-      |121 -> class scala.collection.immutable.TreeMap
-      |122 -> class scala.math.Ordering$Byte$
-      |123 -> class scala.math.Ordering$Short$
-      |124 -> class scala.math.Ordering$Int$
-      |125 -> class scala.math.Ordering$Long$
-      |126 -> class scala.math.Ordering$Float$
-      |127 -> class scala.math.Ordering$Double$
-      |128 -> class scala.math.Ordering$Boolean$
-      |129 -> class scala.math.Ordering$Char$
-      |130 -> class scala.math.Ordering$String$
-      |131 -> class scala.collection.immutable.Set$EmptySet$
-      |132 -> class scala.collection.immutable.ListSet$EmptyListSet$
-      |133 -> class scala.collection.immutable.ListSet$Node
-      |134 -> class scala.collection.immutable.HashSet$EmptyHashSet$
-      |135 -> class scala.collection.immutable.HashSet$HashSet1
-      |136 -> class scala.collection.immutable.Map$EmptyMap$
-      |137 -> class scala.collection.immutable.HashMap$EmptyHashMap$
-      |138 -> class scala.collection.immutable.HashMap$HashMap1
-      |139 -> class scala.collection.immutable.ListMap$EmptyListMap$
-      |140 -> class scala.collection.immutable.ListMap$Node
-      |141 -> class scala.collection.immutable.Stream$Cons
-      |142 -> class scala.collection.immutable.Stream$Empty$
-      |143 -> class scala.runtime.VolatileByteRef
-      |144 -> class scala.math.BigDecimal
-      |145 -> class scala.collection.immutable.Queue$EmptyQueue$
-      |146 -> class scala.collection.immutable.MapLike$$anon$1
-      |147 -> class scala.collection.immutable.MapLike$$anon$2
-      |148 -> class scala.collection.immutable.MapLike$ImmutableDefaultKeySet""".stripMargin.linesIterator.toStream
+      |9 -> class scala.collection.convert.Wrappers$SeqWrapper
+      |10 -> class scala.collection.convert.Wrappers$IteratorWrapper
+      |11 -> class scala.collection.convert.Wrappers$MapWrapper
+      |12 -> class scala.collection.convert.Wrappers$JListWrapper
+      |13 -> class scala.collection.convert.Wrappers$JMapWrapper
+      |14 -> class scala.Some
+      |15 -> class scala.util.Left
+      |16 -> class scala.util.Right
+      |17 -> class scala.collection.immutable.Vector
+      |18 -> class scala.collection.immutable.Set$Set1
+      |19 -> class scala.collection.immutable.Set$Set2
+      |20 -> class scala.collection.immutable.Set$Set3
+      |21 -> class scala.collection.immutable.Set$Set4
+      |22 -> class scala.collection.immutable.HashSet$HashTrieSet
+      |23 -> class scala.collection.immutable.Map$Map1
+      |24 -> class scala.collection.immutable.Map$Map2
+      |25 -> class scala.collection.immutable.Map$Map3
+      |26 -> class scala.collection.immutable.Map$Map4
+      |27 -> class scala.collection.immutable.HashMap$HashTrieMap
+      |28 -> class scala.collection.immutable.Range$Inclusive
+      |29 -> class scala.collection.immutable.NumericRange$Inclusive
+      |30 -> class scala.collection.immutable.NumericRange$Exclusive
+      |31 -> class scala.collection.mutable.BitSet
+      |32 -> class scala.collection.mutable.HashMap
+      |33 -> class scala.collection.mutable.HashSet
+      |34 -> class scala.collection.convert.Wrappers$IterableWrapper
+      |35 -> class scala.Tuple1
+      |36 -> class scala.Tuple2
+      |37 -> class scala.Tuple3
+      |38 -> class scala.Tuple4
+      |39 -> class scala.Tuple5
+      |40 -> class scala.Tuple6
+      |41 -> class scala.Tuple7
+      |42 -> class scala.Tuple8
+      |43 -> class scala.Tuple9
+      |44 -> class scala.Tuple10
+      |45 -> class scala.Tuple11
+      |46 -> class scala.Tuple12
+      |47 -> class scala.Tuple13
+      |48 -> class scala.Tuple14
+      |49 -> class scala.Tuple15
+      |50 -> class scala.Tuple16
+      |51 -> class scala.Tuple17
+      |52 -> class scala.Tuple18
+      |53 -> class scala.Tuple19
+      |54 -> class scala.Tuple20
+      |55 -> class scala.Tuple21
+      |56 -> class scala.Tuple22
+      |57 -> class scala.Tuple1$mcJ$sp
+      |58 -> class scala.Tuple1$mcI$sp
+      |59 -> class scala.Tuple1$mcD$sp
+      |60 -> class scala.Tuple2$mcJJ$sp
+      |61 -> class scala.Tuple2$mcJI$sp
+      |62 -> class scala.Tuple2$mcJD$sp
+      |63 -> class scala.Tuple2$mcIJ$sp
+      |64 -> class scala.Tuple2$mcII$sp
+      |65 -> class scala.Tuple2$mcID$sp
+      |66 -> class scala.Tuple2$mcDJ$sp
+      |67 -> class scala.Tuple2$mcDI$sp
+      |68 -> class scala.Tuple2$mcDD$sp
+      |69 -> class scala.Symbol
+      |70 -> interface scala.reflect.ClassTag
+      |71 -> class scala.runtime.BoxedUnit
+      |72 -> class java.util.Arrays$ArrayList
+      |73 -> class java.util.BitSet
+      |74 -> class java.util.PriorityQueue
+      |75 -> class java.util.regex.Pattern
+      |76 -> class java.sql.Date
+      |77 -> class java.sql.Time
+      |78 -> class java.sql.Timestamp
+      |79 -> class java.net.URI
+      |80 -> class java.net.InetSocketAddress
+      |81 -> class java.util.UUID
+      |82 -> class java.util.Locale
+      |83 -> class java.text.SimpleDateFormat
+      |84 -> class java.util.Collections$UnmodifiableCollection
+      |85 -> class java.util.Collections$UnmodifiableRandomAccessList
+      |86 -> class java.util.Collections$UnmodifiableList
+      |87 -> class java.util.Collections$UnmodifiableMap
+      |88 -> class java.util.Collections$UnmodifiableSet
+      |89 -> class java.util.Collections$UnmodifiableSortedMap
+      |90 -> class java.util.Collections$UnmodifiableSortedSet
+      |91 -> class com.esotericsoftware.kryo.kryo5.serializers.ClosureSerializer$Closure
+      |92 -> class [B
+      |93 -> class [S
+      |94 -> class [I
+      |95 -> class [J
+      |96 -> class [F
+      |97 -> class [D
+      |98 -> class [Z
+      |99 -> class [C
+      |100 -> class [Ljava.lang.String;
+      |101 -> class [Ljava.lang.Object;
+      |102 -> class java.lang.Class
+      |103 -> class java.lang.Object
+      |104 -> class scala.collection.mutable.WrappedArray$ofByte
+      |105 -> class scala.collection.mutable.WrappedArray$ofShort
+      |106 -> class scala.collection.mutable.WrappedArray$ofInt
+      |107 -> class scala.collection.mutable.WrappedArray$ofLong
+      |108 -> class scala.collection.mutable.WrappedArray$ofFloat
+      |109 -> class scala.collection.mutable.WrappedArray$ofDouble
+      |110 -> class scala.collection.mutable.WrappedArray$ofBoolean
+      |111 -> class scala.collection.mutable.WrappedArray$ofChar
+      |112 -> class scala.collection.mutable.WrappedArray$ofRef
+      |113 -> class scala.None$
+      |114 -> class scala.collection.immutable.Queue
+      |115 -> class scala.collection.immutable.Nil$
+      |116 -> class scala.collection.immutable.$colon$colon
+      |117 -> class scala.collection.immutable.Range
+      |118 -> class scala.collection.immutable.WrappedString
+      |119 -> class scala.collection.immutable.TreeSet
+      |120 -> class scala.collection.immutable.TreeMap
+      |121 -> class scala.math.Ordering$Byte$
+      |122 -> class scala.math.Ordering$Short$
+      |123 -> class scala.math.Ordering$Int$
+      |124 -> class scala.math.Ordering$Long$
+      |125 -> class scala.math.Ordering$Float$
+      |126 -> class scala.math.Ordering$Double$
+      |127 -> class scala.math.Ordering$Boolean$
+      |128 -> class scala.math.Ordering$Char$
+      |129 -> class scala.math.Ordering$String$
+      |130 -> class scala.collection.immutable.Set$EmptySet$
+      |131 -> class scala.collection.immutable.ListSet$EmptyListSet$
+      |132 -> class scala.collection.immutable.ListSet$Node
+      |133 -> class scala.collection.immutable.HashSet$EmptyHashSet$
+      |134 -> class scala.collection.immutable.HashSet$HashSet1
+      |135 -> class scala.collection.immutable.Map$EmptyMap$
+      |136 -> class scala.collection.immutable.HashMap$EmptyHashMap$
+      |137 -> class scala.collection.immutable.HashMap$HashMap1
+      |138 -> class scala.collection.immutable.ListMap$EmptyListMap$
+      |139 -> class scala.collection.immutable.ListMap$Node
+      |140 -> class scala.collection.immutable.Stream$Cons
+      |141 -> class scala.collection.immutable.Stream$Empty$
+      |142 -> class scala.runtime.VolatileByteRef
+      |143 -> class scala.math.BigDecimal
+      |144 -> class scala.collection.immutable.Queue$EmptyQueue$
+      |145 -> class scala.collection.immutable.MapLike$$anon$1
+      |146 -> class scala.collection.immutable.MapLike$$anon$2
+      |147 -> class scala.collection.immutable.MapLike$ImmutableDefaultKeySet""".stripMargin.linesIterator.toStream
 
   val RecentEntries = Stream.empty
 
diff --git a/chill-scala/src/test/scala-2.12-/com/twitter/chill/SerializedExamplesData.scala b/chill-scala/src/test/scala-2.12-/com/twitter/chill/SerializedExamplesData.scala
index e5103576..28337b71 100644
--- a/chill-scala/src/test/scala-2.12-/com/twitter/chill/SerializedExamplesData.scala
+++ b/chill-scala/src/test/scala-2.12-/com/twitter/chill/SerializedExamplesData.scala
@@ -25,192 +25,194 @@ object SerializedExamplesData {
   val Examples = Seq(
     0 -> ("AgI=" -> Int.box(1)),
     1 -> ("AwFhYuM=" -> "abc"),
-    2 -> ("BD+AAAA=" -> Float.box(1)),
+    2 -> ("BAAAgD8=" -> Float.box(1)),
     3 -> ("BQE=" -> Boolean.box(true)),
     4 -> ("BgE=" -> Byte.box(1)),
-    5 -> ("BwBh" -> Char.box('a')),
-    6 -> ("CAAB" -> Short.box(1)),
+    5 -> ("B2EA" -> Char.box('a')),
+    6 -> ("CAEA" -> Short.box(1)),
     7 -> ("CQI=" -> Long.box(1)),
-    8 -> ("Cj/wAAAAAAAA" -> Double.box(1)),
+    8 -> ("CgAAAAAAAPA/" -> Double.box(1)),
     // 9 -> void is a special case
     // Note: Instead of JavaConverters.***Converter(***).as***, in Scala 2.12
     // methods JavaConverters.*** can be used directly. For backwards compatibility,
     // the legacy methods to convert are used here.
-    10 -> ("DAEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBdwEBAgQ=" ->
+    9 -> ("CwEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBdgEBAgQ=" ->
       JavaConverters.seqAsJavaListConverter(Seq(2)).asJava), // Wrappers$SeqWrapper
-    11 -> ("DQEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBAQFzY2FsYS5jb2xsZWN0aW9uLkluZGV4ZWRTZXFMaWtlJEVsZW1lbnTzAW0BAQIBYQECBAIA" ->
+    10 -> ("DAEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBAQFzY2FsYS5jb2xsZWN0aW9uLkluZGV4ZWRTZXFMaWtlJEVsZW1lbnTzAWwBAQIBYAECBAIA" ->
       JavaConverters.asJavaIteratorConverter(Iterator(2)).asJava), // Wrappers$IteratorWrapper
-    12 -> ("DgEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBGgEBJwECBAIE" ->
+    11 -> ("DQEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBGQEBJgECBAIE" ->
       JavaConverters.mapAsJavaMapConverter(Map(2 -> 2)).asJava), // Wrappers$MapWrapper
-    13 -> ("DwEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBAQFqYXZhLnV0aWwuQ29sbGVjdGlvbnMkU2luZ2xldG9uTGlz9AECBA==" ->
+    12 -> ("DgEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBAQFqYXZhLnV0aWwuQ29sbGVjdGlvbnMkU2luZ2xldG9uTGlz9AECBA==" ->
       JavaConverters
         .asScalaBufferConverter(_root_.java.util.Collections.singletonList(2))
         .asScala), // Wrappers$JListWrapper
-    14 -> ("EAEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBAQFqYXZhLnV0aWwuQ29sbGVjdGlvbnMkU2luZ2xldG9uTWHwAQIEAgQ=" ->
+    13 -> ("DwEBAHNjYWxhLmNvbGxlY3Rpb24uY29udmVydC5XcmFwcGVyc6QBAQFqYXZhLnV0aWwuQ29sbGVjdGlvbnMkU2luZ2xldG9uTWHwAQIEAgQ=" ->
       JavaConverters
         .mapAsScalaMapConverter(_root_.java.util.Collections.singletonMap(2, 2))
         .asScala), // Wrappers$JMapWrapper
-    15 -> ("EQECBA==" -> Some(2)),
-    16 -> ("EgECBA==" -> Left(2)),
-    17 -> ("EwECBA==" -> Right(2)),
-    18 -> ("FAEBAgQ=" -> Vector(2)),
-    19 -> ("FQEBAgQ=" -> Set(2)),
-    20 -> ("FgECAgQCBg==" -> Set(2, 3)),
-    21 -> ("FwEDAgQCBgII" -> Set(2, 3, 4)),
-    22 -> ("GAEEAgQCBgIIAgo=" -> Set(2, 3, 4, 5)),
-    // 23 -> class HashSet$HashTrieSet
-    24 -> ("GgEBJwECBAIG" -> Map(2 -> 3)),
-    25 -> ("GwECJwECBAIGJwECCAIK" -> Map(2 -> 3, 4 -> 5)),
-    26 -> ("HAEDJwECBAIGJwECCAIKJwECDAIO" -> Map(2 -> 3, 4 -> 5, 6 -> 7)),
-    27 -> ("HQEEJwECBAIGJwECCAIKJwECDAIOJwECEAIS" -> Map(2 -> 3, 4 -> 5, 6 -> 7, 8 -> 9)),
-    // 28 -> class HashMap$HashTrieMap
-    29 -> ("HwEMAAwIBgI=" -> new Range.Inclusive(3, 6, 1)),
-    30 -> ("IAEBAgoAAQABAHNjYWxhLm1hdGguTnVtZXJpYyRJbnRJc0ludGVncmFspAEBAAMIAgQCAg==" ->
+    14 -> ("EAECBA==" -> Some(2)),
+    15 -> ("EQECBA==" -> Left(2)),
+    16 -> ("EgECBA==" -> Right(2)),
+    17 -> ("EwEBAgQ=" -> Vector(2)),
+    18 -> ("FAEBAgQ=" -> Set(2)),
+    19 -> ("FQECAgQCBg==" -> Set(2, 3)),
+    20 -> ("FgEDAgQCBgII" -> Set(2, 3, 4)),
+    21 -> ("FwEEAgQCBgIIAgo=" -> Set(2, 3, 4, 5)),
+    // 22 -> class HashSet$HashTrieSet
+    23 -> ("GQEBJgECBAIG" -> Map(2 -> 3)),
+    24 -> ("GgECJgECBAIGJgECCAIK" -> Map(2 -> 3, 4 -> 5)),
+    25 -> ("GwEDJgECBAIGJgECCAIKJgECDAIO" -> Map(2 -> 3, 4 -> 5, 6 -> 7)),
+    26 -> ("HAEEJgECBAIGJgECCAIKJgECDAIOJgECEAIS" -> Map(2 -> 3, 4 -> 5, 6 -> 7, 8 -> 9)),
+    // 27 -> class HashMap$HashTrieMap
+    28 -> ("HgEMAAwIBgI=" -> new Range.Inclusive(3, 6, 1)),
+    29 -> ("HwEBAgoAAQABAHNjYWxhLm1hdGguTnVtZXJpYyRJbnRJc0ludGVncmFspAEBAAMIAgQCAg==" ->
       new NumericRange.Inclusive[Int](2, 5, 1)),
-    31 -> ("IQEBAgoAAAABAHNjYWxhLm1hdGguTnVtZXJpYyRJbnRJc0ludGVncmFspAEBAAMGAgQCAg==" ->
+    30 -> ("IAEBAgoAAAABAHNjYWxhLm1hdGguTnVtZXJpYyRJbnRJc0ludGVncmFspAEBAAMGAgQCAg==" ->
       new NumericRange.Exclusive[Int](2, 5, 1)),
-    32 -> ("IgECAgYCCg==" -> scala.collection.mutable.BitSet(3, 5)),
-    33 -> ("IwEBJwECBgIK" -> scala.collection.mutable.HashMap(3 -> 5)),
-    34 -> ("JAEBAgY=" -> scala.collection.mutable.HashSet(3)),
-    35 -> ("JQF3AQECBA==" -> Seq(2).asJavaCollection), // Wrappers$IterableWrapper
-    36 -> ("JgEDAYJh" -> Tuple1("a")),
-    37 -> ("JwEDAYJhAwGCYg==" -> ("a", "b")),
-    38 -> ("KAECAgIEAgY=" -> (1, 2, 3)),
-    39 -> ("KQECAgIEAgYCCA==" -> (1, 2, 3, 4)),
-    40 -> ("KgECAgIEAgYCCAIK" -> (1, 2, 3, 4, 5)),
-    41 -> ("KwECAgIEAgYCCAIKAgw=" -> (1, 2, 3, 4, 5, 6)),
-    42 -> ("LAECAgIEAgYCCAIKAgwCDg==" -> (1, 2, 3, 4, 5, 6, 7)),
-    43 -> ("LQECAgIEAgYCCAIKAgwCDgIQ" -> (1, 2, 3, 4, 5, 6, 7, 8)),
-    44 -> ("LgECAgIEAgYCCAIKAgwCDgIQAhI=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9)),
-    45 -> ("LwECAgIEAgYCCAIKAgwCDgIQAhICAA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0)),
-    46 -> ("MAECAgIEAgYCCAIKAgwCDgIQAhICAAIC" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1)),
-    47 -> ("MQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQ=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2)),
-    48 -> ("MgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBg==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3)),
-    49 -> ("MwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgII" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4)),
-    50 -> ("NAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgo=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5)),
-    51 -> ("NQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6)),
-    52 -> ("NgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIO" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7)),
-    53 -> ("NwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhA=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8)),
-    54 -> ("OAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEg==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)),
-    55 -> ("OQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIA" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0)),
-    56 -> ("OgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIAAgI=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1)),
-    57 -> ("OwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIAAgICBA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2)),
-    58 -> ("PAEAAAAAAAAAAQ==" -> Tuple1(1L)),
-    59 -> ("PQEAAAAB" -> Tuple1(1)),
-    60 -> ("PgE/8AAAAAAAAA==" -> Tuple1(1.0)),
-    61 -> ("PwEAAAAAAAAAAQAAAAAAAAAC" -> (1L, 2L)),
-    62 -> ("QAEAAAAAAAAAAQAAAAI=" -> (1L, 2)),
-    63 -> ("QQEAAAAAAAAAAUAAAAAAAAAA" -> (1L, 2.0)),
-    64 -> ("QgEAAAABAAAAAAAAAAI=" -> (1, 2L)),
-    65 -> ("QwEAAAABAAAAAg==" -> (1, 2)),
-    66 -> ("RAEAAAABQAAAAAAAAAA=" -> (1, 2.0)),
-    67 -> ("RQE/8AAAAAAAAAAAAAAAAAAC" -> (1.0, 2L)),
-    68 -> ("RgE/8AAAAAAAAAAAAAI=" -> (1.0, 2)),
-    69 -> ("RwE/8AAAAAAAAEAAAAAAAAAA" -> (1.0, 2.0)),
-    70 -> ("SAGCYQ==" -> Symbol("a")),
-    // 71 -> interface scala.reflect.ClassTag
-    72 -> ("SgE=" -> runtime.BoxedUnit.UNIT),
-    73 -> ("SwEDagICAgQCBg==" -> _root_.java.util.Arrays.asList(1, 2, 3)),
-    74 -> ("TAECAAAAAAAAAAAAAAAAAAAAAA==" -> new _root_.java.util.BitSet(65)),
-    75 -> ("TQEAAA==" -> new _root_.java.util.PriorityQueue[Int](7)),
-    76 -> ("TgFhKuI=" -> _root_.java.util.regex.Pattern.compile("a*b")),
-    77 -> ("TwEA" -> new _root_.java.sql.Date(0)),
-    78 -> ("UAEH" -> new _root_.java.sql.Time(7)),
-    79 -> ("UQEDwI23AQ==" -> new _root_.java.sql.Timestamp(3)),
-    80 -> ("UgGB" -> new _root_.java.net.URI("")),
-    81 -> ("UwEwLjAuMC6wAg==" -> new _root_.java.net.InetSocketAddress(2)),
-    82 -> ("VAECBA==" -> new _root_.java.util.UUID(1, 2)),
-    83 -> ("VQGs7QAFc3IAEGphdmEudXRpbC5Mb2NhbGV++BFgnDD57AMABkkACGhhc2hjb2RlTAAHY291bnRyeXQAEkxqYXZhL2xhbmcvU3RyaW5nO0wACmV4dGVuc2lvbnNxAH4AAUwACGxhbmd1YWdlcQB+AAFMAAZzY3JpcHRxAH4AAUwAB3ZhcmlhbnRxAH4AAXhw/////3QAAHEAfgADdAACZW5xAH4AA3EAfgADeA==" ->
+    31 -> ("IQECAgYCCg==" -> scala.collection.mutable.BitSet(3, 5)),
+    32 -> ("IgEBJgECBgIK" -> scala.collection.mutable.HashMap(3 -> 5)),
+    33 -> ("IwEBAgY=" -> scala.collection.mutable.HashSet(3)),
+    34 -> ("JAF2AQECBA==" -> Seq(2).asJavaCollection), // Wrappers$IterableWrapper
+    35 -> ("JQEDAYJh" -> Tuple1("a")),
+    36 -> ("JgEDAYJhAwGCYg==" -> ("a", "b")),
+    37 -> ("JwECAgIEAgY=" -> (1, 2, 3)),
+    38 -> ("KAECAgIEAgYCCA==" -> (1, 2, 3, 4)),
+    39 -> ("KQECAgIEAgYCCAIK" -> (1, 2, 3, 4, 5)),
+    40 -> ("KgECAgIEAgYCCAIKAgw=" -> (1, 2, 3, 4, 5, 6)),
+    41 -> ("KwECAgIEAgYCCAIKAgwCDg==" -> (1, 2, 3, 4, 5, 6, 7)),
+    42 -> ("LAECAgIEAgYCCAIKAgwCDgIQ" -> (1, 2, 3, 4, 5, 6, 7, 8)),
+    43 -> ("LQECAgIEAgYCCAIKAgwCDgIQAhI=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9)),
+    44 -> ("LgECAgIEAgYCCAIKAgwCDgIQAhICAA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0)),
+    45 -> ("LwECAgIEAgYCCAIKAgwCDgIQAhICAAIC" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1)),
+    46 -> ("MAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQ=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2)),
+    47 -> ("MQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBg==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3)),
+    48 -> ("MgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgII" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4)),
+    49 -> ("MwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgo=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5)),
+    50 -> ("NAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6)),
+    51 -> ("NQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIO" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7)),
+    52 -> ("NgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhA=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8)),
+    53 -> ("NwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEg==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)),
+    54 -> ("OAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIA" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0)),
+    55 -> ("OQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIAAgI=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1)),
+    56 -> ("OgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIAAgICBA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2)),
+    57 -> ("OwEBAAAAAAAAAA==" -> Tuple1(1L)),
+    58 -> ("PAEBAAAA" -> Tuple1(1)),
+    59 -> ("PQEAAAAAAADwPw==" -> Tuple1(1.0)),
+    60 -> ("PgEBAAAAAAAAAAIAAAAAAAAA" -> (1L, 2L)),
+    61 -> ("PwEBAAAAAAAAAAIAAAA=" -> (1L, 2)),
+    62 -> ("QAEBAAAAAAAAAAAAAAAAAABA" -> (1L, 2.0)),
+    63 -> ("QQEBAAAAAgAAAAAAAAA=" -> (1, 2L)),
+    64 -> ("QgEBAAAAAgAAAA==" -> (1, 2)),
+    65 -> ("QwEBAAAAAAAAAAAAAEA=" -> (1, 2.0)),
+    66 -> ("RAEAAAAAAADwPwIAAAAAAAAA" -> (1.0, 2L)),
+    67 -> ("RQEAAAAAAADwPwIAAAA=" -> (1.0, 2)),
+    68 -> ("RgEAAAAAAADwPwAAAAAAAABA" -> (1.0, 2.0)),
+    69 -> ("RwGCYQ==" -> Symbol("a")),
+    // 70 -> interface scala.reflect.ClassTag
+    71 -> ("SQE=" -> runtime.BoxedUnit.UNIT),
+    72 -> ("SgEDaQICAgQCBg==" -> _root_.java.util.Arrays.asList(1, 2, 3)),
+    73 -> ("SwECAAAAAAAAAAAAAAAAAAAAAA==" -> new _root_.java.util.BitSet(65)),
+    74 -> ("TAEAAA==" -> new _root_.java.util.PriorityQueue[Int](7)),
+    75 -> ("TQFhKuI=" -> _root_.java.util.regex.Pattern.compile("a*b")),
+    76 -> ("TgEA" -> new _root_.java.sql.Date(0)),
+    77 -> ("TwEH" -> new _root_.java.sql.Time(7)),
+    78 -> ("UAEDwI23AQ==" -> new _root_.java.sql.Timestamp(3)),
+    79 -> ("UQGB" -> new _root_.java.net.URI("")),
+    80 -> ("UgEwLjAuMC6wAg==" -> new _root_.java.net.InetSocketAddress(2)),
+    81 -> ("UwECBA==" -> new _root_.java.util.UUID(1, 2)),
+    82 -> ("VAGs7QAFc3IAEGphdmEudXRpbC5Mb2NhbGV++BFgnDD57AMABkkACGhhc2hjb2RlTAAHY291bnRyeXQAEkxqYXZhL2xhbmcvU3RyaW5nO0wACmV4dGVuc2lvbnNxAH4AAUwACGxhbmd1YWdlcQB+AAFMAAZzY3JpcHRxAH4AAUwAB3ZhcmlhbnRxAH4AAXhw/////3QAAHEAfgADdAACZW5xAH4AA3EAfgADeA==" ->
       _root_.java.util.Locale.ENGLISH),
-    // 84 -> class java.text.SimpleDateFormat - this case has two very special aspects:
+    // 83 -> class java.text.SimpleDateFormat - this case has two very special aspects:
     // a) SimpleDateFormat("") serializes to about 40.000 bytes
     // b) each time you serialize SimpleDateFormat(""), you get a slightly different binary representation.
     // Probably, one should write a custom serializer for this class...
-    85 -> ("VwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eUxpc/QB" ->
+    84 -> ("VgEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eUxpc/QB" ->
       _root_.java.util.Collections.unmodifiableCollection(_root_.java.util.Collections.EMPTY_LIST)),
-    86 -> ("WAEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eUxpc/QB" ->
+    85 -> ("VwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eUxpc/QB" ->
       _root_.java.util.Collections.unmodifiableList(_root_.java.util.Collections.EMPTY_LIST)),
-    87 -> ("WQEBAGphdmEudXRpbC5MaW5rZWRMaXP0AQA=" ->
+    86 -> ("WAEBAGphdmEudXRpbC5MaW5rZWRMaXP0AQE=" ->
       _root_.java.util.Collections.unmodifiableList(new _root_.java.util.LinkedList[Int]())),
-    88 -> ("WgEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRTaW5nbGV0b25NYfABAgICBA==" ->
+    87 -> ("WQEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRTaW5nbGV0b25NYfABAgICBA==" ->
       _root_.java.util.Collections
         .unmodifiableMap[Int, Int](_root_.java.util.Collections.singletonMap(1, 2))),
-    89 -> ("WwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eVNl9AE=" ->
+    88 -> ("WgEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eVNl9AE=" ->
       _root_.java.util.Collections.unmodifiableSet(_root_.java.util.Collections.EMPTY_SET)),
-    90 -> ("XAEBAMEBamF2YS51dGlsLkNvbGxlY3Rpb25zJFVubW9kaWZpYWJsZU5hdmlnYWJsZU1hcCRFbXB0eU5hdmlnYWJsZU1hcAEA" ->
+    89 -> ("WwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRVbm1vZGlmaWFibGVOYXZpZ2FibGVNYXAkRW1wdHlOYXZpZ2FibGVNYfABAQ==" ->
       _root_.java.util.Collections
         .unmodifiableSortedMap[Int, Int](_root_.java.util.Collections.emptySortedMap())),
-    // 91 -> class java.util.Collections$UnmodifiableSortedSet
+    // 90 -> class java.util.Collections$UnmodifiableSortedSet
     // With the following implementation, we have a problem
-    // 91 -> ("XQEBAMEBamF2YS51dGlsLkNvbGxlY3Rpb25zJFVubW9kaWZpYWJsZU5hdmlnYWJsZVNldCRFbXB0eU5hdmlnYWJsZVNldAEA" ->
+    // 90 -> ("XQEBAMEBamF2YS51dGlsLkNvbGxlY3Rpb25zJFVubW9kaWZpYWJsZU5hdmlnYWJsZVNldCRFbXB0eU5hdmlnYWJsZVNldAEA" ->
     //   _root_.java.util.Collections.unmodifiableSortedSet[Int](_root_.java.util.Collections.emptySortedSet())),
     // because we get an exception in the test with the root cause:
     // com.twitter.chill.Instantiators$ can not access a member of class java.util.Collections$UnmodifiableNavigableSet$EmptyNavigableSet with modifiers "public"
-    // 92 -> class com.esotericsoftware.kryo.serializers.ClosureSerializer$Closure"""
-    93 -> ("XwECgA==" -> Array(Byte.MinValue)),
-    94 -> ("YAECf/8=" -> Array(Short.MaxValue)),
-    95 -> ("YQEC/////w8=" -> Array(Int.MinValue)),
-    96 -> ("YgEC/v//////////" -> Array(Long.MaxValue)),
-    97 -> ("YwECAAAAAQ==" -> Array(Float.MinPositiveValue)),
-    98 -> ("ZAEC/+////////8=" -> Array(Double.MinValue)),
-    99 -> ("ZQECAQ==" -> Array(true)),
-    100 -> ("ZgECAHg=" -> Array('x')),
-    101 -> ("ZwECAWNh9A==" -> Array("cat")),
-    102 -> ("aAEDAgQDAW1vdXPl" -> Array(2, "mouse")),
-    103 -> ("aQECAQ==" -> classOf[Int]),
-    104 -> ("agE=" -> new Object()),
-    105 -> ("awEBBgFfAQKA" -> wrapByteArray(Array(Byte.MinValue))),
-    106 -> ("bAEBCAFgAQJ//w==" -> wrapShortArray(Array(Short.MaxValue))),
-    107 -> ("bQEBAgFhAQL/////Dw==" -> wrapIntArray(Array(Int.MinValue))),
-    108 -> ("bgEBCQFiAQL+//////////8=" -> wrapLongArray(Array(Long.MaxValue))),
-    109 -> ("bwEBBAFjAQIAAAAB" -> wrapFloatArray(Array(Float.MinPositiveValue))),
-    110 -> ("cAEBCgFkAQL/7////////w==" -> wrapDoubleArray(Array(Double.MinValue))),
-    111 -> ("cQEBBQFlAQIB" -> wrapBooleanArray(Array(true))),
-    112 -> ("cgEBBwFmAQIAeA==" -> wrapCharArray(Array('x'))),
-    113 -> ("cwEBAwBnAQIBY2H0" -> wrapRefArray(Array("cat"))),
-    114 -> ("dAE=" -> None),
-    115 -> ("dQEA" -> collection.immutable.Queue()),
-    116 -> ("dgEA" -> Nil),
-    117 -> ("dwEBAgQ=" -> (2 :: Nil)),
-    118 -> ("eAEGAAQEAgI=" -> collection.immutable.Range(1, 3)),
-    119 -> ("eQEBdGHj" -> wrapString("tac")),
-    120 -> ("egECfgECBAIG" -> collection.immutable.TreeSet(3, 2)),
-    121 -> ("ewEBfgEnAQIGAgQ=" -> collection.immutable.TreeMap(3 -> 2)),
-    122 -> ("fAE=" -> math.Ordering.Byte),
-    123 -> ("fQE=" -> math.Ordering.Short),
-    124 -> ("fgE=" -> math.Ordering.Int),
-    125 -> ("fwE=" -> math.Ordering.Long),
-    126 -> ("gAEB" -> math.Ordering.Float),
-    127 -> ("gQEB" -> math.Ordering.Double),
-    128 -> ("ggEB" -> math.Ordering.Boolean),
-    129 -> ("gwEB" -> math.Ordering.Char),
-    130 -> ("hAEB" -> math.Ordering.String),
-    131 -> ("hQEBAA==" -> Set[Any]()),
-    132 -> ("hgEBAA==" -> ListSet[Any]()),
-    133 -> ("hwEBAUgBgmE=" -> ListSet[Any]('a)),
-    134 -> ("iAEBAA==" -> HashSet[Any]()),
-    135 -> ("iQEBAUgBgmE=" -> HashSet[Any]('a)),
-    136 -> ("igEBAA==" -> Map[Any, Any]()),
-    137 -> ("iwEBAA==" -> HashMap[Any, Any]()),
-    138 -> ("jAEBAScBSAGCYUgE" -> HashMap('a -> 'a)),
-    139 -> ("jQEBAA==" -> ListMap[Any, Any]()),
-    140 -> ("jgEBAScBSAGCYUgE" -> ListMap('a -> 'a)),
-    141 -> ("jwEBdwEBAgI=" -> Stream(1)),
-    142 -> ("kAEB" -> Stream()),
-    143 -> ("kQEBCg==" -> new VolatileByteRef(10)),
-    144 -> ("kgEBAQBqYXZhLm1hdGguQmlnRGVjaW1h7AECAgA=" -> math.BigDecimal(2)),
-    145 -> ("kwEBAA==" -> (Queue.empty[Any], true)),
-    146 -> ("lAEBAScBAgICBA==" -> (Map(1 -> 2).filterKeys(_ != 2).toMap, true)),
-    147 -> ("lQEBAScBAgICBg==" -> (Map(1 -> 2).mapValues(_ + 1).toMap, true)),
-    148 -> ("lgEBAQIC" -> (Map(1 -> 2).keySet, true))
+    // 91 -> class com.esotericsoftware.kryo.serializers.ClosureSerializer$Closure"""
+    92 -> ("XgECgA==" -> Array(Byte.MinValue)),
+    93 -> ("XwEC/38=" -> Array(Short.MaxValue)),
+    94 -> ("YAEC/////w8=" -> Array(Int.MinValue)),
+    95 -> ("YQEC/v//////////" -> Array(Long.MaxValue)),
+    96 -> ("YgECAQAAAA==" -> Array(Float.MinPositiveValue)),
+    97 -> ("YwEC////////7/8=" -> Array(Double.MinValue)),
+    98 -> ("ZAECAQ==" -> Array(true)),
+    99 -> ("ZQECeAA=" -> Array('x')),
+    100 -> ("ZgECAWNh9A==" -> Array("cat")),
+    101 -> ("ZwEDAgQDAW1vdXPl" -> Array(2, "mouse")),
+    102 -> ("aAECAQ==" -> classOf[Int]),
+    103 -> ("aQE=" -> new Object()),
+    104 -> ("agEBBgFeAQKA" -> wrapByteArray(Array(Byte.MinValue))),
+    105 -> ("awEBCAFfAQL/fw==" -> wrapShortArray(Array(Short.MaxValue))),
+    106 -> ("bAEBAgFgAQL/////Dw==" -> wrapIntArray(Array(Int.MinValue))),
+    107 -> ("bQEBCQFhAQL+//////////8=" -> wrapLongArray(Array(Long.MaxValue))),
+    108 -> ("bgEBBAFiAQIBAAAA" -> wrapFloatArray(Array(Float.MinPositiveValue))),
+    109 -> ("bwEBCgFjAQL////////v/w==" -> wrapDoubleArray(Array(Double.MinValue))),
+    110 -> ("cAEBBQFkAQIB" -> wrapBooleanArray(Array(true))),
+    111 -> ("cQEBBwFlAQJ4AA==" -> wrapCharArray(Array('x'))),
+    112 -> ("cgEBA2YBAgFjYfQ=" -> wrapRefArray(Array("cat"))),
+    113 -> ("cwE=" -> None),
+    114 -> ("dAEA" -> collection.immutable.Queue()),
+    115 -> ("dQEA" -> Nil),
+    116 -> ("dgEBAgQ=" -> (2 :: Nil)),
+    117 -> ("dwEGAAQEAgI=" -> collection.immutable.Range(1, 3)),
+    118 -> ("eAEBdGHj" -> wrapString("tac")),
+    119 -> ("eQECfQECBAIG" -> collection.immutable.TreeSet(3, 2)),
+    120 -> ("egEBfQEmAQIGAgQ=" -> collection.immutable.TreeMap(3 -> 2)),
+    121 -> ("ewE=" -> math.Ordering.Byte),
+    122 -> ("fAE=" -> math.Ordering.Short),
+    123 -> ("fQE=" -> math.Ordering.Int),
+    124 -> ("fgE=" -> math.Ordering.Long),
+    125 -> ("fwE=" -> math.Ordering.Float),
+    126 -> ("gAEB" -> math.Ordering.Double),
+    127 -> ("gQEB" -> math.Ordering.Boolean),
+    128 -> ("ggEB" -> math.Ordering.Char),
+    129 -> ("gwEB" -> math.Ordering.String),
+    130 -> ("hAEBAA==" -> Set[Any]()),
+    131 -> ("hQEBAA==" -> ListSet[Any]()),
+    132 -> ("hgEBAUcBgmE=" -> ListSet[Any]('a)),
+    133 -> ("hwEBAA==" -> HashSet[Any]()),
+    134 -> ("iAEBAUcBgmE=" -> HashSet[Any]('a)),
+    135 -> ("iQEBAA==" -> Map[Any, Any]()),
+    136 -> ("igEBAA==" -> HashMap[Any, Any]()),
+    137 -> ("iwEBASYBRwGCYUcE" -> HashMap('a -> 'a)),
+    138 -> ("jAEBAA==" -> ListMap[Any, Any]()),
+    139 -> ("jQEBASYBRwGCYUcE" -> ListMap('a -> 'a)),
+    140 -> ("jgEBdgEBAgI=" -> Stream(1)),
+    141 -> ("jwEB" -> Stream()),
+    142 -> ("kAEBCg==" -> new VolatileByteRef(10)),
+    143 -> ("kQEBAQBqYXZhLm1hdGguQmlnRGVjaW1h7AECAgA=" -> math.BigDecimal(2)),
+    144 -> ("kgEBAA==" -> (Queue.empty[Any], true)),
+    145 -> ("kwEBASYBAgICBA==" -> (Map(1 -> 2).filterKeys(_ != 2).toMap, true)),
+    146 -> ("lAEBASYBAgICBg==" -> (Map(1 -> 2).mapValues(_ + 1).toMap, true)),
+    147 -> ("lQEBAQIC" -> (Map(1 -> 2).keySet, true))
   )
 
-  val SpecialCasesNotInExamplesMap: Seq[Int] = Seq(9, 23, 28, 71, 84, 91, 92)
+  val SpecialCasesNotInExamplesMap: Seq[Int] = Seq(22, 27, 70, 83, 90, 91)
 
   // In older Scala versions, instances of the following classes have a serialized representation that differs from
-  // the current Scala version 2.12.6:
-  // 11 -> scala.collection.convert.Wrappers.IteratorWrapper
-  // 29 -> scala.collection.immutable.Range$Inclusive
+  // the current Scala version 2.12.17:
+  // 10 -> scala.collection.convert.Wrappers.IteratorWrapper
+  // 28 -> scala.collection.immutable.Range$Inclusive
+  // 117 -> scala.collection.immutable.Range
+
   val OmitExamplesInScalaVersion: Map[String, Seq[Int]] =
-    Map("2.10." -> Seq(11, 29, 118), "2.11." -> Seq(29, 118))
+    Map("2.10." -> Seq(10, 28, 117), "2.11." -> Seq(28, 117))
 }
diff --git a/chill-scala/src/test/scala-2.13+/com/twitter/chill/RegistrationIdsSpecData.scala b/chill-scala/src/test/scala-2.13+/com/twitter/chill/RegistrationIdsSpecData.scala
index 21d0f931..2ce87b7c 100644
--- a/chill-scala/src/test/scala-2.13+/com/twitter/chill/RegistrationIdsSpecData.scala
+++ b/chill-scala/src/test/scala-2.13+/com/twitter/chill/RegistrationIdsSpecData.scala
@@ -28,150 +28,158 @@ object RegistrationIdsSpecData {
       |6 -> short
       |7 -> long
       |8 -> double
-      |9 -> void
-      |10 -> class scala.collection.convert.JavaCollectionWrappers$SeqWrapper
-      |11 -> class scala.collection.convert.JavaCollectionWrappers$IteratorWrapper
-      |12 -> class scala.collection.convert.JavaCollectionWrappers$MapWrapper
-      |13 -> class scala.collection.convert.JavaCollectionWrappers$JListWrapper
-      |14 -> class scala.collection.convert.JavaCollectionWrappers$JMapWrapper
-      |15 -> class scala.Some
-      |16 -> class scala.util.Left
-      |17 -> class scala.util.Right
-      |18 -> class scala.collection.immutable.Vector
-      |19 -> class scala.collection.immutable.Set$Set1
-      |20 -> class scala.collection.immutable.Set$Set2
-      |21 -> class scala.collection.immutable.Set$Set3
-      |22 -> class scala.collection.immutable.Set$Set4
-      |23 -> class scala.collection.immutable.HashSet
-      |24 -> class scala.collection.immutable.Map$Map1
-      |25 -> class scala.collection.immutable.Map$Map2
-      |26 -> class scala.collection.immutable.Map$Map3
-      |27 -> class scala.collection.immutable.Map$Map4
-      |28 -> class scala.collection.immutable.HashMap
-      |29 -> class scala.collection.immutable.Range$Inclusive
-      |30 -> class scala.collection.immutable.NumericRange$Inclusive
-      |31 -> class scala.collection.immutable.NumericRange$Exclusive
-      |32 -> class scala.collection.mutable.BitSet
-      |33 -> class scala.collection.mutable.HashMap
-      |34 -> class scala.collection.mutable.HashSet
-      |35 -> class scala.collection.convert.JavaCollectionWrappers$IterableWrapper
-      |36 -> class scala.Tuple1
-      |37 -> class scala.Tuple2
-      |38 -> class scala.Tuple3
-      |39 -> class scala.Tuple4
-      |40 -> class scala.Tuple5
-      |41 -> class scala.Tuple6
-      |42 -> class scala.Tuple7
-      |43 -> class scala.Tuple8
-      |44 -> class scala.Tuple9
-      |45 -> class scala.Tuple10
-      |46 -> class scala.Tuple11
-      |47 -> class scala.Tuple12
-      |48 -> class scala.Tuple13
-      |49 -> class scala.Tuple14
-      |50 -> class scala.Tuple15
-      |51 -> class scala.Tuple16
-      |52 -> class scala.Tuple17
-      |53 -> class scala.Tuple18
-      |54 -> class scala.Tuple19
-      |55 -> class scala.Tuple20
-      |56 -> class scala.Tuple21
-      |57 -> class scala.Tuple22
-      |58 -> class scala.Tuple1$mcJ$sp
-      |59 -> class scala.Tuple1$mcI$sp
-      |60 -> class scala.Tuple1$mcD$sp
-      |61 -> class scala.Tuple2$mcJJ$sp
-      |62 -> class scala.Tuple2$mcJI$sp
-      |63 -> class scala.Tuple2$mcJD$sp
-      |64 -> class scala.Tuple2$mcIJ$sp
-      |65 -> class scala.Tuple2$mcII$sp
-      |66 -> class scala.Tuple2$mcID$sp
-      |67 -> class scala.Tuple2$mcDJ$sp
-      |68 -> class scala.Tuple2$mcDI$sp
-      |69 -> class scala.Tuple2$mcDD$sp
-      |70 -> class scala.Symbol
-      |71 -> interface scala.reflect.ClassTag
-      |72 -> class scala.runtime.BoxedUnit
-      |73 -> class java.util.Arrays$ArrayList
-      |74 -> class java.util.BitSet
-      |75 -> class java.util.PriorityQueue
-      |76 -> class java.util.regex.Pattern
-      |77 -> class java.sql.Date
-      |78 -> class java.sql.Time
-      |79 -> class java.sql.Timestamp
-      |80 -> class java.net.URI
-      |81 -> class java.net.InetSocketAddress
-      |82 -> class java.util.UUID
-      |83 -> class java.util.Locale
-      |84 -> class java.text.SimpleDateFormat
-      |85 -> class java.util.Collections$UnmodifiableCollection
-      |86 -> class java.util.Collections$UnmodifiableRandomAccessList
-      |87 -> class java.util.Collections$UnmodifiableList
-      |88 -> class java.util.Collections$UnmodifiableMap
-      |89 -> class java.util.Collections$UnmodifiableSet
-      |90 -> class java.util.Collections$UnmodifiableSortedMap
-      |91 -> class java.util.Collections$UnmodifiableSortedSet
-      |92 -> class com.esotericsoftware.kryo.serializers.ClosureSerializer$Closure
-      |93 -> class scala.collection.immutable.Range$Exclusive
-      |94 -> class [B
-      |95 -> class [S
-      |96 -> class [I
-      |97 -> class [J
-      |98 -> class [F
-      |99 -> class [D
-      |100 -> class [Z
-      |101 -> class [C
-      |102 -> class [Ljava.lang.String;
-      |103 -> class [Ljava.lang.Object;
-      |104 -> class java.lang.Class
-      |105 -> class java.lang.Object
-      |106 -> class scala.collection.mutable.ArraySeq$ofByte
-      |107 -> class scala.collection.mutable.ArraySeq$ofShort
-      |108 -> class scala.collection.mutable.ArraySeq$ofInt
-      |109 -> class scala.collection.mutable.ArraySeq$ofLong
-      |110 -> class scala.collection.mutable.ArraySeq$ofFloat
-      |111 -> class scala.collection.mutable.ArraySeq$ofDouble
-      |112 -> class scala.collection.mutable.ArraySeq$ofBoolean
-      |113 -> class scala.collection.mutable.ArraySeq$ofChar
-      |114 -> class scala.collection.mutable.ArraySeq$ofRef
-      |115 -> class scala.None$
-      |116 -> class scala.collection.immutable.Queue
-      |117 -> class scala.collection.immutable.Nil$
-      |118 -> class scala.collection.immutable.$colon$colon
-      |119 -> class scala.collection.immutable.Range
-      |120 -> class scala.collection.immutable.WrappedString
-      |121 -> class scala.collection.immutable.TreeSet
-      |122 -> class scala.collection.immutable.TreeMap
-      |123 -> class scala.math.Ordering$Byte$
-      |124 -> class scala.math.Ordering$Short$
-      |125 -> class scala.math.Ordering$Int$
-      |126 -> class scala.math.Ordering$Long$
-      |127 -> class scala.math.Ordering$Float$
-      |128 -> class scala.math.Ordering$Double$
-      |129 -> class scala.math.Ordering$Boolean$
-      |130 -> class scala.math.Ordering$Char$
-      |131 -> class scala.math.Ordering$String$
-      |132 -> class scala.collection.immutable.Set$EmptySet$
-      |133 -> class scala.collection.immutable.ListSet$EmptyListSet$
-      |134 -> class scala.collection.immutable.ListSet$Node
-      |135 -> class scala.collection.immutable.Map$EmptyMap$
-      |136 -> class scala.collection.immutable.ListMap$EmptyListMap$
-      |137 -> class scala.collection.immutable.ListMap$Node
-      |138 -> class scala.collection.immutable.Stream$Cons
-      |139 -> class scala.collection.immutable.Stream$Empty$
-      |140 -> class scala.runtime.VolatileByteRef
-      |141 -> class scala.math.BigDecimal
-      |142 -> class scala.collection.immutable.Queue$EmptyQueue$
-      |143 -> class scala.collection.immutable.MapOps$ImmutableKeySet""".stripMargin.linesIterator.toStream
+      |9 -> class scala.collection.convert.JavaCollectionWrappers$SeqWrapper
+      |10 -> class scala.collection.convert.JavaCollectionWrappers$IteratorWrapper
+      |11 -> class scala.collection.convert.JavaCollectionWrappers$MapWrapper
+      |12 -> class scala.collection.convert.JavaCollectionWrappers$JListWrapper
+      |13 -> class scala.collection.convert.JavaCollectionWrappers$JMapWrapper
+      |14 -> class scala.Some
+      |15 -> class scala.util.Left
+      |16 -> class scala.util.Right
+      |17 -> class scala.collection.immutable.Vector
+      |18 -> class scala.collection.immutable.Set$Set1
+      |19 -> class scala.collection.immutable.Set$Set2
+      |20 -> class scala.collection.immutable.Set$Set3
+      |21 -> class scala.collection.immutable.Set$Set4
+      |22 -> class scala.collection.immutable.HashSet
+      |23 -> class scala.collection.immutable.Map$Map1
+      |24 -> class scala.collection.immutable.Map$Map2
+      |25 -> class scala.collection.immutable.Map$Map3
+      |26 -> class scala.collection.immutable.Map$Map4
+      |27 -> class scala.collection.immutable.HashMap
+      |28 -> class scala.collection.immutable.Range$Inclusive
+      |29 -> class scala.collection.immutable.NumericRange$Inclusive
+      |30 -> class scala.collection.immutable.NumericRange$Exclusive
+      |31 -> class scala.collection.mutable.BitSet
+      |32 -> class scala.collection.mutable.HashMap
+      |33 -> class scala.collection.mutable.HashSet
+      |34 -> class scala.collection.convert.JavaCollectionWrappers$IterableWrapper
+      |35 -> class scala.Tuple1
+      |36 -> class scala.Tuple2
+      |37 -> class scala.Tuple3
+      |38 -> class scala.Tuple4
+      |39 -> class scala.Tuple5
+      |40 -> class scala.Tuple6
+      |41 -> class scala.Tuple7
+      |42 -> class scala.Tuple8
+      |43 -> class scala.Tuple9
+      |44 -> class scala.Tuple10
+      |45 -> class scala.Tuple11
+      |46 -> class scala.Tuple12
+      |47 -> class scala.Tuple13
+      |48 -> class scala.Tuple14
+      |49 -> class scala.Tuple15
+      |50 -> class scala.Tuple16
+      |51 -> class scala.Tuple17
+      |52 -> class scala.Tuple18
+      |53 -> class scala.Tuple19
+      |54 -> class scala.Tuple20
+      |55 -> class scala.Tuple21
+      |56 -> class scala.Tuple22
+      |57 -> class scala.Tuple1$mcJ$sp
+      |58 -> class scala.Tuple1$mcI$sp
+      |59 -> class scala.Tuple1$mcD$sp
+      |60 -> class scala.Tuple2$mcJJ$sp
+      |61 -> class scala.Tuple2$mcJI$sp
+      |62 -> class scala.Tuple2$mcJD$sp
+      |63 -> class scala.Tuple2$mcIJ$sp
+      |64 -> class scala.Tuple2$mcII$sp
+      |65 -> class scala.Tuple2$mcID$sp
+      |66 -> class scala.Tuple2$mcDJ$sp
+      |67 -> class scala.Tuple2$mcDI$sp
+      |68 -> class scala.Tuple2$mcDD$sp
+      |69 -> class scala.Symbol
+      |70 -> interface scala.reflect.ClassTag
+      |71 -> class scala.runtime.BoxedUnit
+      |72 -> class java.util.Arrays$ArrayList
+      |73 -> class java.util.BitSet
+      |74 -> class java.util.PriorityQueue
+      |75 -> class java.util.regex.Pattern
+      |76 -> class java.sql.Date
+      |77 -> class java.sql.Time
+      |78 -> class java.sql.Timestamp
+      |79 -> class java.net.URI
+      |80 -> class java.net.InetSocketAddress
+      |81 -> class java.util.UUID
+      |82 -> class java.util.Locale
+      |83 -> class java.text.SimpleDateFormat
+      |84 -> class java.util.Collections$UnmodifiableCollection
+      |85 -> class java.util.Collections$UnmodifiableRandomAccessList
+      |86 -> class java.util.Collections$UnmodifiableList
+      |87 -> class java.util.Collections$UnmodifiableMap
+      |88 -> class java.util.Collections$UnmodifiableSet
+      |89 -> class java.util.Collections$UnmodifiableSortedMap
+      |90 -> class java.util.Collections$UnmodifiableSortedSet
+      |91 -> class com.esotericsoftware.kryo.kryo5.serializers.ClosureSerializer$Closure
+      |92 -> class scala.collection.immutable.Range$Exclusive
+      |93 -> class [B
+      |94 -> class [S
+      |95 -> class [I
+      |96 -> class [J
+      |97 -> class [F
+      |98 -> class [D
+      |99 -> class [Z
+      |100 -> class [C
+      |101 -> class [Ljava.lang.String;
+      |102 -> class [Ljava.lang.Object;
+      |103 -> class java.lang.Class
+      |104 -> class java.lang.Object
+      |105 -> class scala.collection.mutable.ArraySeq$ofByte
+      |106 -> class scala.collection.mutable.ArraySeq$ofShort
+      |107 -> class scala.collection.mutable.ArraySeq$ofInt
+      |108 -> class scala.collection.mutable.ArraySeq$ofLong
+      |109 -> class scala.collection.mutable.ArraySeq$ofFloat
+      |110 -> class scala.collection.mutable.ArraySeq$ofDouble
+      |111 -> class scala.collection.mutable.ArraySeq$ofBoolean
+      |112 -> class scala.collection.mutable.ArraySeq$ofChar
+      |113 -> class scala.collection.mutable.ArraySeq$ofRef
+      |114 -> class scala.None$
+      |115 -> class scala.collection.immutable.Queue
+      |116 -> class scala.collection.immutable.Nil$
+      |117 -> class scala.collection.immutable.$colon$colon
+      |118 -> class scala.collection.immutable.Range
+      |119 -> class scala.collection.immutable.WrappedString
+      |120 -> class scala.collection.immutable.TreeSet
+      |121 -> class scala.collection.immutable.TreeMap
+      |122 -> class scala.math.Ordering$Byte$
+      |123 -> class scala.math.Ordering$Short$
+      |124 -> class scala.math.Ordering$Int$
+      |125 -> class scala.math.Ordering$Long$
+      |126 -> class scala.math.Ordering$Float$
+      |127 -> class scala.math.Ordering$Double$
+      |128 -> class scala.math.Ordering$Boolean$
+      |129 -> class scala.math.Ordering$Char$
+      |130 -> class scala.math.Ordering$String$
+      |131 -> class scala.collection.immutable.Set$EmptySet$
+      |132 -> class scala.collection.immutable.ListSet$EmptyListSet$
+      |133 -> class scala.collection.immutable.ListSet$Node
+      |134 -> class scala.collection.immutable.Map$EmptyMap$
+      |135 -> class scala.collection.immutable.ListMap$EmptyListMap$
+      |136 -> class scala.collection.immutable.ListMap$Node
+      |137 -> class scala.collection.immutable.Stream$Cons
+      |138 -> class scala.collection.immutable.Stream$Empty$
+      |139 -> class scala.runtime.VolatileByteRef
+      |140 -> class scala.math.BigDecimal
+      |141 -> class scala.collection.immutable.Queue$EmptyQueue$
+      |142 -> class scala.collection.immutable.MapOps$ImmutableKeySet""".stripMargin.linesIterator.toStream
 
   val RecentEntries =
-    """144 -> class scala.collection.immutable.Vector0$
-      |145 -> class scala.collection.immutable.Vector1
-      |146 -> class scala.collection.immutable.Vector2
-      |147 -> class scala.collection.immutable.Vector3
-      |148 -> class scala.collection.immutable.Vector4
-      |149 -> class scala.collection.immutable.Vector5
-      |150 -> class scala.collection.immutable.Vector6""".stripMargin.linesIterator.toStream
+    """143 -> class scala.collection.immutable.Vector0$
+      |144 -> class scala.collection.immutable.Vector1
+      |145 -> class scala.collection.immutable.Vector2
+      |146 -> class scala.collection.immutable.Vector3
+      |147 -> class scala.collection.immutable.Vector4
+      |148 -> class scala.collection.immutable.Vector5
+      |149 -> class scala.collection.immutable.Vector6
+      |150 -> class scala.collection.immutable.ArraySeq$ofByte
+      |151 -> class scala.collection.immutable.ArraySeq$ofShort
+      |152 -> class scala.collection.immutable.ArraySeq$ofInt
+      |153 -> class scala.collection.immutable.ArraySeq$ofLong
+      |154 -> class scala.collection.immutable.ArraySeq$ofFloat
+      |155 -> class scala.collection.immutable.ArraySeq$ofDouble
+      |156 -> class scala.collection.immutable.ArraySeq$ofBoolean
+      |157 -> class scala.collection.immutable.ArraySeq$ofChar
+      |158 -> class scala.collection.immutable.ArraySeq$ofRef""".stripMargin.linesIterator.toStream
 
   val CurrentEntries = Entries_0_9_5 #::: RecentEntries
 }
diff --git a/chill-scala/src/test/scala-2.13+/com/twitter/chill/SerializedExamplesData.scala b/chill-scala/src/test/scala-2.13+/com/twitter/chill/SerializedExamplesData.scala
index 7dd21274..6b704bd6 100644
--- a/chill-scala/src/test/scala-2.13+/com/twitter/chill/SerializedExamplesData.scala
+++ b/chill-scala/src/test/scala-2.13+/com/twitter/chill/SerializedExamplesData.scala
@@ -18,207 +18,207 @@ package com.twitter.chill
 
 import scala.collection.JavaConverters
 import scala.collection.JavaConverters._
-import scala.collection.immutable.{ArraySeq, HashMap, HashSet, ListMap, ListSet, NumericRange, Queue}
+import scala.collection.immutable.{ArraySeq, ListMap, ListSet, NumericRange, Queue}
 import scala.runtime.VolatileByteRef
 
 object SerializedExamplesData {
   val Examples = Seq(
     0 -> ("AgI=" -> Int.box(1)),
     1 -> ("AwFhYuM=" -> "abc"),
-    2 -> ("BD+AAAA=" -> Float.box(1)),
+    2 -> ("BAAAgD8=" -> Float.box(1)),
     3 -> ("BQE=" -> Boolean.box(true)),
     4 -> ("BgE=" -> Byte.box(1)),
-    5 -> ("BwBh" -> Char.box('a')),
-    6 -> ("CAAB" -> Short.box(1)),
+    5 -> ("B2EA" -> Char.box('a')),
+    6 -> ("CAEA" -> Short.box(1)),
     7 -> ("CQI=" -> Long.box(1)),
-    8 -> ("Cj/wAAAAAAAA" -> Double.box(1)),
+    8 -> ("CgAAAAAAAPA/" -> Double.box(1)),
     // 9 -> void is a special case
     // Note: Instead of JavaConverters.***Converter(***).as***, in Scala 2.12
     // methods JavaConverters.*** can be used directly. For backwards compatibility,
     // the legacy methods to convert are used here.
-    10 -> ("DAF4AQECBA==" ->
+    9 -> ("CwF3AQECBA==" ->
       JavaConverters.seqAsJavaListConverter(Seq(2)).asJava), // Wrappers$SeqWrapper
-    11 -> ("DQEBAHNjYWxhLmNvbGxlY3Rpb24uQXJyYXlPcHMkQXJyYXlJdGVyYXRvciRtY0kkc/ABAgBiAQIEBA==" ->
+    10 -> ("DAEBAHNjYWxhLmNvbGxlY3Rpb24uQXJyYXlPcHMkQXJyYXlJdGVyYXRvciRtY0kkc/ABAgBhAQIEBA==" ->
       JavaConverters.asJavaIteratorConverter(Iterator(2)).asJava), // Wrappers$IteratorWrapper
-    12 -> ("DgEaAQEnAQIEAgQ=" ->
+    11 -> ("DQEZAQEmAQIEAgQ=" ->
       JavaConverters.mapAsJavaMapConverter(Map(2 -> 2)).asJava), // Wrappers$MapWrapper
-    13 -> ("DwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRTaW5nbGV0b25MaXP0AQIE" ->
+    12 -> ("DgEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRTaW5nbGV0b25MaXP0AQIE" ->
       JavaConverters
         .asScalaBufferConverter(_root_.java.util.Collections.singletonList(2))
         .asScala), // Wrappers$JListWrapper
-    14 -> ("EAEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRTaW5nbGV0b25NYfABAgQCBA==" ->
+    13 -> ("DwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRTaW5nbGV0b25NYfABAgQCBA==" ->
       JavaConverters
         .mapAsScalaMapConverter(_root_.java.util.Collections.singletonMap(2, 2))
         .asScala), // Wrappers$JMapWrapper
-    15 -> ("EQECBA==" -> Some(2)),
-    16 -> ("EgECBA==" -> Left(2)),
-    17 -> ("EwECBA==" -> Right(2)),
-    // 18 -> ("FAEBAgQ=" -> Vector(2)),
+    14 -> ("EAECBA==" -> Some(2)),
+    15 -> ("EQECBA==" -> Left(2)),
+    16 -> ("EgECBA==" -> Right(2)),
+    // 17 -> ("FAEBAgQ=" -> Vector(2)),
     // new vector classes in 2.13 see 144, 145
-    19 -> ("FQEBAgQ=" -> Set(2)),
-    20 -> ("FgECAgQCBg==" -> Set(2, 3)),
-    21 -> ("FwEDAgQCBgII" -> Set(2, 3, 4)),
-    22 -> ("GAEEAgQCBgIIAgo=" -> Set(2, 3, 4, 5)),
-    23 -> ("GQEA" -> HashSet.empty[Any]),
-    24 -> ("GgEBJwECBAIG" -> Map(2 -> 3)),
-    25 -> ("GwECJwECBAIGJwECCAIK" -> Map(2 -> 3, 4 -> 5)),
-    26 -> ("HAEDJwECBAIGJwECCAIKJwECDAIO" -> Map(2 -> 3, 4 -> 5, 6 -> 7)),
-    27 -> ("HQEEJwECBAIGJwECCAIKJwECDAIOJwECEAIS" -> Map(2 -> 3, 4 -> 5, 6 -> 7, 8 -> 9)),
-    28 -> ("HgEA" -> HashMap.empty[Any, Any]),
-    29 -> ("HwEMAAwIBgI=" -> new Range.Inclusive(3, 6, 1)),
-    30 -> ("IAECAgoAAAEAAQBzY2FsYS5tYXRoLk51bWVyaWMkSW50SXNJbnRlZ3JhbKQBAQADAgQCAg==" ->
+    18 -> ("FAEBAgQ=" -> Set(2)),
+    19 -> ("FQECAgQCBg==" -> Set(2, 3)),
+    20 -> ("FgEDAgQCBgII" -> Set(2, 3, 4)),
+    21 -> ("FwEEAgQCBgIIAgo=" -> Set(2, 3, 4, 5)),
+    // 22 -> class HashSet$HashTrieSet
+    23 -> ("GQEBJgECBAIG" -> Map(2 -> 3)),
+    24 -> ("GgECJgECBAIGJgECCAIK" -> Map(2 -> 3, 4 -> 5)),
+    25 -> ("GwEDJgECBAIGJgECCAIKJgECDAIO" -> Map(2 -> 3, 4 -> 5, 6 -> 7)),
+    26 -> ("HAEEJgECBAIGJgECCAIKJgECDAIOJgECEAIS" -> Map(2 -> 3, 4 -> 5, 6 -> 7, 8 -> 9)),
+    // 27 -> class HashMap$HashTrieMap
+    28 -> ("HgEMAAwIBgI=" -> new Range.Inclusive(3, 6, 1)),
+    29 -> ("HwECAgoAAAEAAQBzY2FsYS5tYXRoLk51bWVyaWMkSW50SXNJbnRlZ3JhbKQBAQADAgQCAg==" ->
       new NumericRange.Inclusive[Int](2, 5, 1)),
-    31 -> ("IQECAgoAAAAAAQBzY2FsYS5tYXRoLk51bWVyaWMkSW50SXNJbnRlZ3JhbKQBAQADAgQCAg==" ->
+    30 -> ("IAECAgoAAAAAAQBzY2FsYS5tYXRoLk51bWVyaWMkSW50SXNJbnRlZ3JhbKQBAQADAgQCAg==" ->
       new NumericRange.Exclusive[Int](2, 5, 1)),
-    32 -> ("IgECAgYCCg==" -> scala.collection.mutable.BitSet(3, 5)),
-    33 -> ("IwEBJwECBgIK" -> scala.collection.mutable.HashMap(3 -> 5)),
-    34 -> ("JAEBAgY=" -> scala.collection.mutable.HashSet(3)),
-    35 -> ("JQF4AQECBA==" -> Seq(2).asJavaCollection), // Wrappers$IterableWrapper
-    36 -> ("JgEDAYJh" -> Tuple1("a")),
-    37 -> ("JwEDAYJhAwGCYg==" -> ("a", "b")),
-    38 -> ("KAECAgIEAgY=" -> (1, 2, 3)),
-    39 -> ("KQECAgIEAgYCCA==" -> (1, 2, 3, 4)),
-    40 -> ("KgECAgIEAgYCCAIK" -> (1, 2, 3, 4, 5)),
-    41 -> ("KwECAgIEAgYCCAIKAgw=" -> (1, 2, 3, 4, 5, 6)),
-    42 -> ("LAECAgIEAgYCCAIKAgwCDg==" -> (1, 2, 3, 4, 5, 6, 7)),
-    43 -> ("LQECAgIEAgYCCAIKAgwCDgIQ" -> (1, 2, 3, 4, 5, 6, 7, 8)),
-    44 -> ("LgECAgIEAgYCCAIKAgwCDgIQAhI=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9)),
-    45 -> ("LwECAgIEAgYCCAIKAgwCDgIQAhICAA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0)),
-    46 -> ("MAECAgIEAgYCCAIKAgwCDgIQAhICAAIC" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1)),
-    47 -> ("MQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQ=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2)),
-    48 -> ("MgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBg==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3)),
-    49 -> ("MwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgII" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4)),
-    50 -> ("NAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgo=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5)),
-    51 -> ("NQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6)),
-    52 -> ("NgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIO" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7)),
-    53 -> ("NwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhA=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8)),
-    54 -> ("OAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEg==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)),
-    55 -> ("OQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIA" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0)),
-    56 -> ("OgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIAAgI=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1)),
-    57 -> ("OwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIAAgICBA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2)),
-    58 -> ("PAEAAAAAAAAAAQ==" -> Tuple1(1L)),
-    59 -> ("PQEAAAAB" -> Tuple1(1)),
-    60 -> ("PgE/8AAAAAAAAA==" -> Tuple1(1.0)),
-    61 -> ("PwEAAAAAAAAAAQAAAAAAAAAC" -> (1L, 2L)),
-    62 -> ("QAEAAAAAAAAAAQAAAAI=" -> (1L, 2)),
-    63 -> ("QQEAAAAAAAAAAUAAAAAAAAAA" -> (1L, 2.0)),
-    64 -> ("QgEAAAABAAAAAAAAAAI=" -> (1, 2L)),
-    65 -> ("QwEAAAABAAAAAg==" -> (1, 2)),
-    66 -> ("RAEAAAABQAAAAAAAAAA=" -> (1, 2.0)),
-    67 -> ("RQE/8AAAAAAAAAAAAAAAAAAC" -> (1.0, 2L)),
-    68 -> ("RgE/8AAAAAAAAAAAAAI=" -> (1.0, 2)),
-    69 -> ("RwE/8AAAAAAAAEAAAAAAAAAA" -> (1.0, 2.0)),
-    70 -> ("SAGCYQ==" -> Symbol("a")),
-    // 71 -> interface scala.reflect.ClassTag
-    72 -> ("SgE=" -> runtime.BoxedUnit.UNIT),
-    73 -> ("SwEDawICAgQCBg==" -> _root_.java.util.Arrays.asList(1, 2, 3)),
-    74 -> ("TAECAAAAAAAAAAAAAAAAAAAAAA==" -> new _root_.java.util.BitSet(65)),
-    75 -> ("TQEAAA==" -> new _root_.java.util.PriorityQueue[Int](7)),
-    76 -> ("TgFhKuI=" -> _root_.java.util.regex.Pattern.compile("a*b")),
-    77 -> ("TwEA" -> new _root_.java.sql.Date(0)),
-    78 -> ("UAEH" -> new _root_.java.sql.Time(7)),
-    79 -> ("UQEDwI23AQ==" -> new _root_.java.sql.Timestamp(3)),
-    80 -> ("UgGB" -> new _root_.java.net.URI("")),
-    81 -> ("UwEwLjAuMC6wAg==" -> new _root_.java.net.InetSocketAddress(2)),
-    82 -> ("VAECBA==" -> new _root_.java.util.UUID(1, 2)),
-    83 -> ("VQGs7QAFc3IAEGphdmEudXRpbC5Mb2NhbGV++BFgnDD57AMABkkACGhhc2hjb2RlTAAHY291bnRyeXQAEkxqYXZhL2xhbmcvU3RyaW5nO0wACmV4dGVuc2lvbnNxAH4AAUwACGxhbmd1YWdlcQB+AAFMAAZzY3JpcHRxAH4AAUwAB3ZhcmlhbnRxAH4AAXhw/////3QAAHEAfgADdAACZW5xAH4AA3EAfgADeA==" ->
+    31 -> ("IQECAgYCCg==" -> scala.collection.mutable.BitSet(3, 5)),
+    32 -> ("IgEBJgECBgIK" -> scala.collection.mutable.HashMap(3 -> 5)),
+    33 -> ("IwEBAgY=" -> scala.collection.mutable.HashSet(3)),
+    34 -> ("JAF3AQECBA==" -> Seq(2).asJavaCollection), // Wrappers$IterableWrapper
+    35 -> ("JQEDAYJh" -> Tuple1("a")),
+    36 -> ("JgEDAYJhAwGCYg==" -> ("a", "b")),
+    37 -> ("JwECAgIEAgY=" -> (1, 2, 3)),
+    38 -> ("KAECAgIEAgYCCA==" -> (1, 2, 3, 4)),
+    39 -> ("KQECAgIEAgYCCAIK" -> (1, 2, 3, 4, 5)),
+    40 -> ("KgECAgIEAgYCCAIKAgw=" -> (1, 2, 3, 4, 5, 6)),
+    41 -> ("KwECAgIEAgYCCAIKAgwCDg==" -> (1, 2, 3, 4, 5, 6, 7)),
+    42 -> ("LAECAgIEAgYCCAIKAgwCDgIQ" -> (1, 2, 3, 4, 5, 6, 7, 8)),
+    43 -> ("LQECAgIEAgYCCAIKAgwCDgIQAhI=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9)),
+    44 -> ("LgECAgIEAgYCCAIKAgwCDgIQAhICAA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0)),
+    45 -> ("LwECAgIEAgYCCAIKAgwCDgIQAhICAAIC" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1)),
+    46 -> ("MAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQ=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2)),
+    47 -> ("MQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBg==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3)),
+    48 -> ("MgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgII" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4)),
+    49 -> ("MwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgo=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5)),
+    50 -> ("NAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6)),
+    51 -> ("NQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIO" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7)),
+    52 -> ("NgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhA=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8)),
+    53 -> ("NwECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEg==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9)),
+    54 -> ("OAECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIA" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0)),
+    55 -> ("OQECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIAAgI=" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1)),
+    56 -> ("OgECAgIEAgYCCAIKAgwCDgIQAhICAAICAgQCBgIIAgoCDAIOAhACEgIAAgICBA==" -> (1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 1, 2)),
+    57 -> ("OwEBAAAAAAAAAA==" -> Tuple1(1L)),
+    58 -> ("PAEBAAAA" -> Tuple1(1)),
+    59 -> ("PQEAAAAAAADwPw==" -> Tuple1(1.0)),
+    60 -> ("PgEBAAAAAAAAAAIAAAAAAAAA" -> (1L, 2L)),
+    61 -> ("PwEBAAAAAAAAAAIAAAA=" -> (1L, 2)),
+    62 -> ("QAEBAAAAAAAAAAAAAAAAAABA" -> (1L, 2.0)),
+    63 -> ("QQEBAAAAAgAAAAAAAAA=" -> (1, 2L)),
+    64 -> ("QgEBAAAAAgAAAA==" -> (1, 2)),
+    65 -> ("QwEBAAAAAAAAAAAAAEA=" -> (1, 2.0)),
+    66 -> ("RAEAAAAAAADwPwIAAAAAAAAA" -> (1.0, 2L)),
+    67 -> ("RQEAAAAAAADwPwIAAAA=" -> (1.0, 2)),
+    68 -> ("RgEAAAAAAADwPwAAAAAAAABA" -> (1.0, 2.0)),
+    69 -> ("RwGCYQ==" -> Symbol("a")),
+    // 70 -> interface scala.reflect.ClassTag
+    71 -> ("SQE=" -> runtime.BoxedUnit.UNIT),
+    72 -> ("SgEDagICAgQCBg==" -> _root_.java.util.Arrays.asList(1, 2, 3)),
+    73 -> ("SwECAAAAAAAAAAAAAAAAAAAAAA==" -> new _root_.java.util.BitSet(65)),
+    74 -> ("TAEAAA==" -> new _root_.java.util.PriorityQueue[Int](7)),
+    75 -> ("TQFhKuI=" -> _root_.java.util.regex.Pattern.compile("a*b")),
+    76 -> ("TgEA" -> new _root_.java.sql.Date(0)),
+    77 -> ("TwEH" -> new _root_.java.sql.Time(7)),
+    78 -> ("UAEDwI23AQ==" -> new _root_.java.sql.Timestamp(3)),
+    79 -> ("UQGB" -> new _root_.java.net.URI("")),
+    80 -> ("UgEwLjAuMC6wAg==" -> new _root_.java.net.InetSocketAddress(2)),
+    81 -> ("UwECBA==" -> new _root_.java.util.UUID(1, 2)),
+    82 -> ("VAGs7QAFc3IAEGphdmEudXRpbC5Mb2NhbGV++BFgnDD57AMABkkACGhhc2hjb2RlTAAHY291bnRyeXQAEkxqYXZhL2xhbmcvU3RyaW5nO0wACmV4dGVuc2lvbnNxAH4AAUwACGxhbmd1YWdlcQB+AAFMAAZzY3JpcHRxAH4AAUwAB3ZhcmlhbnRxAH4AAXhw/////3QAAHEAfgADdAACZW5xAH4AA3EAfgADeA==" ->
       _root_.java.util.Locale.ENGLISH),
-    // 84 -> class java.text.SimpleDateFormat - this case has two very special aspects:
+    // 83 -> class java.text.SimpleDateFormat - this case has two very special aspects:
     // a) SimpleDateFormat("") serializes to about 40.000 bytes
     // b) each time you serialize SimpleDateFormat(""), you get a slightly different binary representation.
     // Probably, one should write a custom serializer for this class...
-    85 -> ("VwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eUxpc/QB" ->
+    84 -> ("VgEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eUxpc/QB" ->
       _root_.java.util.Collections.unmodifiableCollection(_root_.java.util.Collections.EMPTY_LIST)),
-    86 -> ("WAEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eUxpc/QB" ->
+    85 -> ("VwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eUxpc/QB" ->
       _root_.java.util.Collections.unmodifiableList(_root_.java.util.Collections.EMPTY_LIST)),
-    87 -> ("WQEBAGphdmEudXRpbC5MaW5rZWRMaXP0AQA=" ->
+    86 -> ("WAEBAGphdmEudXRpbC5MaW5rZWRMaXP0AQE=" ->
       _root_.java.util.Collections.unmodifiableList(new _root_.java.util.LinkedList[Int]())),
-    88 -> ("WgEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRTaW5nbGV0b25NYfABAgICBA==" ->
+    87 -> ("WQEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRTaW5nbGV0b25NYfABAgICBA==" ->
       _root_.java.util.Collections
         .unmodifiableMap[Int, Int](_root_.java.util.Collections.singletonMap(1, 2))),
-    89 -> ("WwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eVNl9AE=" ->
+    88 -> ("WgEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRFbXB0eVNl9AE=" ->
       _root_.java.util.Collections.unmodifiableSet(_root_.java.util.Collections.EMPTY_SET)),
-    90 -> ("XAEBAMEBamF2YS51dGlsLkNvbGxlY3Rpb25zJFVubW9kaWZpYWJsZU5hdmlnYWJsZU1hcCRFbXB0eU5hdmlnYWJsZU1hcAEA" ->
+    89 -> ("WwEBAGphdmEudXRpbC5Db2xsZWN0aW9ucyRVbm1vZGlmaWFibGVOYXZpZ2FibGVNYXAkRW1wdHlOYXZpZ2FibGVNYfABAQ==" ->
       _root_.java.util.Collections
         .unmodifiableSortedMap[Int, Int](_root_.java.util.Collections.emptySortedMap())),
-    // 91 -> class java.util.Collections$UnmodifiableSortedSet
+    // 90 -> class java.util.Collections$UnmodifiableSortedSet
     // With the following implementation, we have a problem
-    // 91 -> ("XQEBAMEBamF2YS51dGlsLkNvbGxlY3Rpb25zJFVubW9kaWZpYWJsZU5hdmlnYWJsZVNldCRFbXB0eU5hdmlnYWJsZVNldAEA" ->
+    // 90 -> ("XQEBAMEBamF2YS51dGlsLkNvbGxlY3Rpb25zJFVubW9kaWZpYWJsZU5hdmlnYWJsZVNldCRFbXB0eU5hdmlnYWJsZVNldAEA" ->
     //   _root_.java.util.Collections.unmodifiableSortedSet[Int](_root_.java.util.Collections.emptySortedSet())),
     // because we get an exception in the test with the root cause:
     // com.twitter.chill.Instantiators$ can not access a member of class java.util.Collections$UnmodifiableNavigableSet$EmptyNavigableSet with modifiers "public"
-    // 92 -> class com.esotericsoftware.kryo.serializers.ClosureSerializer$Closure"""
-    93 -> ("XwEGAAQEAgI=" -> collection.immutable.Range(1, 3)),
-    94 -> ("YAECgA==" -> Array(Byte.MinValue)),
-    95 -> ("YQECf/8=" -> Array(Short.MaxValue)),
-    96 -> ("YgEC/////w8=" -> Array(Int.MinValue)),
-    97 -> ("YwEC/v//////////" -> Array(Long.MaxValue)),
-    98 -> ("ZAECAAAAAQ==" -> Array(Float.MinPositiveValue)),
-    99 -> ("ZQEC/+////////8=" -> Array(Double.MinValue)),
-    100 -> ("ZgECAQ==" -> Array(true)),
-    101 -> ("ZwECAHg=" -> Array('x')),
-    102 -> ("aAECAWNh9A==" -> Array("cat")),
-    103 -> ("aQEDAgQDAW1vdXPl" -> Array(2, "mouse")),
-    104 -> ("agECAQ==" -> classOf[Int]),
-    105 -> ("awE=" -> new Object()),
-    106 -> ("bAEBBgFgAQKA" -> wrapByteArray(Array(Byte.MinValue))),
-    107 -> ("bQEBCAFhAQJ//w==" -> wrapShortArray(Array(Short.MaxValue))),
-    108 -> ("bgEBAgFiAQL/////Dw==" -> wrapIntArray(Array(Int.MinValue))),
-    109 -> ("bwEBCQFjAQL+//////////8=" -> wrapLongArray(Array(Long.MaxValue))),
-    110 -> ("cAEBBAFkAQIAAAAB" -> wrapFloatArray(Array(Float.MinPositiveValue))),
-    111 -> ("cQEBCgFlAQL/7////////w==" -> wrapDoubleArray(Array(Double.MinValue))),
-    112 -> ("cgEBBQFmAQIB" -> wrapBooleanArray(Array(true))),
-    113 -> ("cwEBBwFnAQIAeA==" -> wrapCharArray(Array('x'))),
-    114 -> ("dAEBAwBoAQIBY2H0" -> wrapRefArray(Array("cat"))),
-    115 -> ("dQE=" -> None),
-    116 -> ("dgEA" -> collection.immutable.Queue()),
-    117 -> ("dwEA" -> Nil),
-    118 -> ("eAEBAgQ=" -> (2 :: Nil)),
-    // 119 -> ("eAEGAAQEAgI=" -> collection.immutable.Range(1, 3)),
-    120 -> ("egEBdGHj" -> wrapString("tac")),
-    121 -> ("ewECfwECBAIG" -> collection.immutable.TreeSet(3, 2)),
-    122 -> ("fAEBfwEnAQIGAgQ=" -> collection.immutable.TreeMap(3 -> 2)),
-    123 -> ("fQE=" -> math.Ordering.Byte),
-    124 -> ("fgE=" -> math.Ordering.Short),
-    125 -> ("fwE=" -> math.Ordering.Int),
-    126 -> ("gAEB" -> math.Ordering.Long),
-    127 -> ("gQEB" -> math.Ordering.Float),
-    128 -> ("ggEB" -> math.Ordering.Double),
-    129 -> ("gwEB" -> math.Ordering.Boolean),
-    130 -> ("hAEB" -> math.Ordering.Char),
-    131 -> ("hQEB" -> math.Ordering.String),
-    132 -> ("hgEBAA==" -> Set[Any]()),
-    133 -> ("hwEBAA==" -> ListSet[Any]()),
-    134 -> ("iAEBAUgBgmE=" -> ListSet[Any]('a)),
-    135 -> ("iQEBAA==" -> Map[Any, Any]()),
-    136 -> ("igEBAA==" -> ListMap[Any, Any]()),
-    137 -> ("iwEBAScBSAGCYUgE" -> ListMap('a -> 'a)),
-    138 -> ("jAEBeAEBAgI=" -> Stream(1)),
-    139 -> ("jQEB" -> Stream()),
-    140 -> ("jgEBCg==" -> new VolatileByteRef(10)),
-    141 -> ("jwEBAQBqYXZhLm1hdGguQmlnRGVjaW1h7AECAgA=" -> math.BigDecimal(2)),
-    142 -> ("kAEBAA==" -> (Queue.empty[Any], true)),
-    143 -> ("kQEBAQIC" -> (Map(1 -> 2).keySet, true)),
-    144 -> ("kgEBAA==" -> Vector.empty[Int]),
-    145 -> ("kwEBAQIC" -> Vector(1)),
-    146 -> ("lAEBQAIC" + "AgIC" * 42 -> Vector.fill(1 << 5 + 1)(1)),
+    // 91 -> com.esotericsoftware.kryo.kryo5.serializers.ClosureSerializer$Closure
+    92 -> ("XgEGAAQEAgI=" -> collection.immutable.Range(1, 3)),
+    93 -> ("XwECgA==" -> Array(Byte.MinValue)),
+    94 -> ("YAEC/38=" -> Array(Short.MaxValue)),
+    95 -> ("YQEC/////w8=" -> Array(Int.MinValue)),
+    96 -> ("YgEC/v//////////" -> Array(Long.MaxValue)),
+    97 -> ("YwECAQAAAA==" -> Array(Float.MinPositiveValue)),
+    98 -> ("ZAEC////////7/8=" -> Array(Double.MinValue)),
+    99 -> ("ZQECAQ==" -> Array(true)),
+    100 -> ("ZgECeAA=" -> Array('x')),
+    101 -> ("ZwECAWNh9A==" -> Array("cat")),
+    102 -> ("aAEDAgQDAW1vdXPl" -> Array(2, "mouse")),
+    103 -> ("aQECAQ==" -> classOf[Int]),
+    104 -> ("agE=" -> new Object()),
+    105 -> ("awEBBgFfAQKA" -> wrapByteArray(Array(Byte.MinValue))),
+    106 -> ("bAEBCAFgAQL/fw==" -> wrapShortArray(Array(Short.MaxValue))),
+    107 -> ("bQEBAgFhAQL/////Dw==" -> wrapIntArray(Array(Int.MinValue))),
+    108 -> ("bgEBCQFiAQL+//////////8=" -> wrapLongArray(Array(Long.MaxValue))),
+    109 -> ("bwEBBAFjAQIBAAAA" -> wrapFloatArray(Array(Float.MinPositiveValue))),
+    110 -> ("cAEBCgFkAQL////////v/w==" -> wrapDoubleArray(Array(Double.MinValue))),
+    111 -> ("cQEBBQFlAQIB" -> wrapBooleanArray(Array(true))),
+    112 -> ("cgEBBwFmAQJ4AA==" -> wrapCharArray(Array('x'))),
+    113 -> ("cwEBA2cBAgFjYfQ=" -> wrapRefArray(Array("cat"))),
+    114 -> ("dAE=" -> None),
+    115 -> ("dQEA" -> collection.immutable.Queue()),
+    116 -> ("dgEA" -> Nil),
+    117 -> ("dwEBAgQ=" -> (2 :: Nil)),
+    // 118 -> ("dwEGAAQEAgIG" -> collection.immutable.Range(1, 3)),
+    119 -> ("eQEBdGHj" -> wrapString("tac")),
+    120 -> ("egECfgECBAIG" -> collection.immutable.TreeSet(3, 2)),
+    121 -> ("ewEBfgEmAQIGAgQ=" -> collection.immutable.TreeMap(3 -> 2)),
+    122 -> ("fAE=" -> math.Ordering.Byte),
+    123 -> ("fQE=" -> math.Ordering.Short),
+    124 -> ("fgE=" -> math.Ordering.Int),
+    125 -> ("fwE=" -> math.Ordering.Long),
+    126 -> ("gAEB" -> math.Ordering.Float),
+    127 -> ("gQEB" -> math.Ordering.Double),
+    128 -> ("ggEB" -> math.Ordering.Boolean),
+    129 -> ("gwEB" -> math.Ordering.Char),
+    130 -> ("hAEB" -> math.Ordering.String),
+    131 -> ("hQEBAA==" -> Set[Any]()),
+    132 -> ("hgEBAA==" -> ListSet[Any]()),
+    133 -> ("hwEBAUcBgmE=" -> ListSet[Any]('a)),
+    134 -> ("iAEBAA==" -> Map[Any, Any]()),
+    135 -> ("iQEBAA==" -> ListMap[Any, Any]()),
+    136 -> ("igEBASYBRwGCYUcE" -> ListMap('a -> 'a)),
+    137 -> ("iwEBdwEBAgI=" -> Stream(1)),
+    138 -> ("jAEB" -> Stream()),
+    139 -> ("jQEBCg==" -> new VolatileByteRef(10)),
+    140 -> ("jgEBAQBqYXZhLm1hdGguQmlnRGVjaW1h7AECAgA=" -> math.BigDecimal(2)),
+    141 -> ("jwEBAA==" -> (Queue.empty[Any], true)),
+    142 -> ("kAEBAQIC" -> (Map(1 -> 2).keySet, true)),
+    143 -> ("kQEBAA==" -> Vector.empty[Int]),
+    144 -> ("kgEBAQIC" -> Vector(1)),
+    145 -> ("kwEBQA" + "ICAg" * 42 + "IC" -> Vector.fill(1 << 5 + 1)(1)),
     // Skip BigVectors. too slow
-    // 147 -> ("" -> Vector.fill(1 << 10 + 1)(1)),
-    // 148 -> ("" -> Vector.fill(1 << 15 + 1)(1)),
-    // 149 -> ("" -> Vector.fill(1 << 20 + 1)(1)),
-    // 150 -> ("" -> Vector.fill(1 << 25 + 1)(1)),
-    151 -> ("mQEBAQKA" -> ArraySeq(Byte.MinValue)),
-    152 -> ("mgEBAQJ//w==" -> ArraySeq(Short.MaxValue)),
-    153 -> ("mwEBAQL/////Dw==" -> ArraySeq(Int.MinValue)),
-    154 -> ("nAEBAQL+//////////8=" -> ArraySeq(Long.MaxValue)),
-    155 -> ("nQEBAQIAAAAB" -> ArraySeq(Float.MinPositiveValue)),
-    156 -> ("ngEBAQL/7////////w==" -> ArraySeq(Double.MinValue)),
-    157 -> ("nwEBAQIB" -> ArraySeq(true)),
-    158 -> ("oAEBAQIAeA==" -> ArraySeq('x')),
-    159 -> ("oQEBaAECAWNh9A==" -> ArraySeq("cat"))
+    // 146 -> ("" -> Vector.fill(1 << 10 + 1)(1)),
+    // 147 -> ("" -> Vector.fill(1 << 15 + 1)(1)),
+    // 148 -> ("" -> Vector.fill(1 << 20 + 1)(1)),
+    // 149 -> ("" -> Vector.fill(1 << 25 + 1)(1)),
+    150 -> ("mAEBAQKA" -> ArraySeq(Byte.MinValue)),
+    151 -> ("mQEBAQL/fw==" -> ArraySeq(Short.MaxValue)),
+    152 -> ("mgEBAQL/////Dw==" -> ArraySeq(Int.MinValue)),
+    153 -> ("mwEBAQL+//////////8=" -> ArraySeq(Long.MaxValue)),
+    154 -> ("nAEBAQIBAAAA" -> ArraySeq(Float.MinPositiveValue)),
+    155 -> ("nQEBAQL////////v/w==" -> ArraySeq(Double.MinValue)),
+    156 -> ("ngEBAQIB" -> ArraySeq(true)),
+    157 -> ("nwEBAQJ4AA==" -> ArraySeq('x')),
+    158 -> ("oAEBZwECAWNh9A==" -> ArraySeq("cat"))
   )
 
-  val SpecialCasesNotInExamplesMap: Seq[Int] = Seq(9, 18, 71, 84, 91, 92, 119, 147, 148, 149, 150)
+  val SpecialCasesNotInExamplesMap: Seq[Int] = Seq(17, 22, 27, 70, 83, 90, 91, 118, 146, 147, 148, 149)
 
   val OmitExamplesInScalaVersion: Map[String, Seq[Int]] = Map.empty
 }
diff --git a/chill-scala/src/test/scala/com/twitter/chill/ClosureCleanerSpec.scala b/chill-scala/src/test/scala/com/twitter/chill/ClosureCleanerSpec.scala
index 2eef8a99..3f47b59c 100644
--- a/chill-scala/src/test/scala/com/twitter/chill/ClosureCleanerSpec.scala
+++ b/chill-scala/src/test/scala/com/twitter/chill/ClosureCleanerSpec.scala
@@ -92,7 +92,7 @@ class ClosureCleanerSpec extends AnyWordSpec with Matchers {
         Option(j).map(x => x + someSerializableMethod())
       }
       val closure3 = (m: Int) => {
-        Option(m).foreach(x => Option(x).foreach(y => Option(y).foreach(z => someSerializableValue)))
+        Option(m).foreach(x => Option(x).foreach(y => Option(y).foreach(_ => someSerializableValue)))
       }
 
       serializableFn(closure1, before = false, after = true)
@@ -110,7 +110,7 @@ class ClosureCleanerSpec extends AnyWordSpec with Matchers {
         Option(j).map(x => x + someSerializableMethod())
       }
       val closure3 = (m: Int) => {
-        Option(m).foreach(x => Option(x).foreach(y => Option(y).foreach(z => someSerializableValue)))
+        Option(m).foreach(x => Option(x).foreach(y => Option(y).foreach(_ => someSerializableValue)))
       }
 
       serializableFn(closure1, before = false, after = false)
diff --git a/chill-scala/src/test/scala/com/twitter/chill/config/ReflectingInstantiatorTest.scala b/chill-scala/src/test/scala/com/twitter/chill/config/ReflectingInstantiatorTest.scala
index 03a75da1..442c4aee 100644
--- a/chill-scala/src/test/scala/com/twitter/chill/config/ReflectingInstantiatorTest.scala
+++ b/chill-scala/src/test/scala/com/twitter/chill/config/ReflectingInstantiatorTest.scala
@@ -18,8 +18,8 @@ package com.twitter.chill
 
 import com.twitter.chill.config._
 
-import org.objenesis.strategy.InstantiatorStrategy;
-import org.objenesis.strategy.StdInstantiatorStrategy
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.InstantiatorStrategy;
+import com.esotericsoftware.kryo.kryo5.objenesis.strategy.StdInstantiatorStrategy
 import org.scalatest.matchers.should.Matchers
 import org.scalatest.wordspec.AnyWordSpec;
 
@@ -32,13 +32,13 @@ class ReflectingInstantiatorTest extends AnyWordSpec with Matchers {
         serializers = Iterable(
           new ReflectingRegistrar(
             classOf[List[_]],
-            classOf[com.esotericsoftware.kryo.serializers.JavaSerializer]
+            classOf[com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer]
           )
         ),
         defaults = Iterable(
           new ReflectingDefaultRegistrar(
             classOf[List[_]],
-            classOf[com.esotericsoftware.kryo.serializers.JavaSerializer]
+            classOf[com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer]
           )
         ),
         skipMissing = true,
@@ -57,7 +57,7 @@ class ReflectingInstantiatorTest extends AnyWordSpec with Matchers {
       conf.toMap(ReflectingInstantiator.REGISTRATIONS).asInstanceOf[String].split(":").toSet should equal(
         Set(
           "scala.collection.immutable.List",
-          "scala.collection.immutable.List,com.esotericsoftware.kryo.serializers.JavaSerializer"
+          "scala.collection.immutable.List,com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer"
         )
       )
       conf
@@ -65,7 +65,7 @@ class ReflectingInstantiatorTest extends AnyWordSpec with Matchers {
         .asInstanceOf[String]
         .split(":")
         .toSet should equal(
-        Set("scala.collection.immutable.List,com.esotericsoftware.kryo.serializers.JavaSerializer")
+        Set("scala.collection.immutable.List,com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer")
       )
     }
     "roundtrip through a config" in {
@@ -75,13 +75,13 @@ class ReflectingInstantiatorTest extends AnyWordSpec with Matchers {
         serializers = Iterable(
           new ReflectingRegistrar(
             classOf[List[_]],
-            classOf[com.esotericsoftware.kryo.serializers.JavaSerializer]
+            classOf[com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer]
           )
         ),
         defaults = Iterable(
           new ReflectingDefaultRegistrar(
             classOf[List[_]],
-            classOf[com.esotericsoftware.kryo.serializers.JavaSerializer]
+            classOf[com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer]
           )
         ),
         skipMissing = true,
@@ -103,7 +103,7 @@ class ReflectingInstantiatorTest extends AnyWordSpec with Matchers {
         .withRegistrar {
           new ReflectingDefaultRegistrar(
             classOf[List[_]],
-            classOf[com.esotericsoftware.kryo.serializers.JavaSerializer]
+            classOf[com.esotericsoftware.kryo.kryo5.serializers.JavaSerializer]
           )
         }
       try {
diff --git a/chill-scrooge/src/main/scala/com/twitter/chill/scrooge/ScroogeThriftStructSerializer.scala b/chill-scrooge/src/main/scala/com/twitter/chill/scrooge/ScroogeThriftStructSerializer.scala
index 8625eb2a..24d03225 100644
--- a/chill-scrooge/src/main/scala/com/twitter/chill/scrooge/ScroogeThriftStructSerializer.scala
+++ b/chill-scrooge/src/main/scala/com/twitter/chill/scrooge/ScroogeThriftStructSerializer.scala
@@ -16,10 +16,10 @@ limitations under the License.
 
 package com.twitter.chill.scrooge
 
-import com.esotericsoftware.kryo.Kryo
-import com.esotericsoftware.kryo.Serializer
-import com.esotericsoftware.kryo.io.Input
-import com.esotericsoftware.kryo.io.Output
+import com.esotericsoftware.kryo.kryo5.Kryo
+import com.esotericsoftware.kryo.kryo5.Serializer
+import com.esotericsoftware.kryo.kryo5.io.Input
+import com.esotericsoftware.kryo.kryo5.io.Output
 import com.twitter.scrooge.{ThriftStruct, ThriftStructCodec, ThriftStructSerializer}
 import org.apache.thrift.protocol.TBinaryProtocol
 import scala.collection.mutable
@@ -96,10 +96,7 @@ class ScroogeThriftStructSerializer[T <: ThriftStruct] extends Serializer[T] {
         throw new RuntimeException("Could not serialize ThriftStruct of type " + thriftStruct.getClass, e)
     }
 
-  /* nb: thriftStructClass doesn't actually have type Class[T] it has type Class[_ <: T]
-   * this lie is courtesy of the Kryo API
-   * */
-  override def read(kryo: Kryo, input: Input, thriftStructClass: Class[T]): T =
+  override def read(kryo: Kryo, input: Input, thriftStructClass: Class[_ <: T]): T =
     // code reviewers: is this use of an anonymous inner class ok, or should I separate it out into something outside?
     try {
       val thriftStructSerializer = lookupThriftStructSerializer(thriftStructClass)
diff --git a/chill-storm/src/main/java/com/twitter/chill/storm/BlizzardKryoFactory.java b/chill-storm/src/main/java/com/twitter/chill/storm/BlizzardKryoFactory.java
deleted file mode 100644
index 7264c874..00000000
--- a/chill-storm/src/main/java/com/twitter/chill/storm/BlizzardKryoFactory.java
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
-Copyright 2012 Twitter, Inc.
-
-Licensed under the Apache License, Version 2.0 (the "License");
-you may not use this file except in compliance with the License.
-You may obtain a copy of the License at
-
-http://www.apache.org/licenses/LICENSE-2.0
-
-Unless required by applicable law or agreed to in writing, software
-distributed under the License is distributed on an "AS IS" BASIS,
-WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-See the License for the specific language governing permissions and
-limitations under the License.
-*/
-
-package com.twitter.chill.storm;
-
-import org.apache.storm.serialization.IKryoFactory;
-import com.esotericsoftware.kryo.Kryo;
-import java.util.Map;
-
-import com.twitter.chill.KryoInstantiator;
-import com.twitter.chill.config.JavaMapConfig;
-import com.twitter.chill.config.ConfiguredInstantiator;
-import com.twitter.chill.config.ConfigurationException;
-
-/** BlizzardKryoFactory. get it? chilly storm.
- * This is a thin wrapper for using the ConfiguredInstantiator. It
- * creates the entire kryo object in the getKryo method and then
- * doesn't do anything else.
- *
- * To set this up, you probably want to use ConfiguredInstantitator with
- * the JavaMapConfig.
- */
-public class BlizzardKryoFactory implements IKryoFactory {
-  public Kryo getKryo(Map conf) {
-    KryoInstantiator kryoInst;
-    try {
-      kryoInst = new ConfiguredInstantiator(new JavaMapConfig(conf));
-      return kryoInst.newKryo();
-    }
-    catch(ConfigurationException cx) { throw new RuntimeException(cx); }
-  }
-  public void preRegister(Kryo k, Map conf) { }
-  public void postRegister(Kryo k, Map conf) { }
-  public void postDecorate(Kryo k, Map conf) { }
-}
diff --git a/chill-thrift/src/main/java/com/twitter/chill/thrift/TBaseSerializer.java b/chill-thrift/src/main/java/com/twitter/chill/thrift/TBaseSerializer.java
index e1ce9adf..ac546a25 100644
--- a/chill-thrift/src/main/java/com/twitter/chill/thrift/TBaseSerializer.java
+++ b/chill-thrift/src/main/java/com/twitter/chill/thrift/TBaseSerializer.java
@@ -16,10 +16,10 @@
 
 package com.twitter.chill.thrift;
 
-import com.esotericsoftware.kryo.Kryo;
-import com.esotericsoftware.kryo.Serializer;
-import com.esotericsoftware.kryo.io.Input;
-import com.esotericsoftware.kryo.io.Output;
+import com.esotericsoftware.kryo.kryo5.Kryo;
+import com.esotericsoftware.kryo.kryo5.Serializer;
+import com.esotericsoftware.kryo.kryo5.io.Input;
+import com.esotericsoftware.kryo.kryo5.io.Output;
 
 import org.apache.thrift.TBase;
 import org.apache.thrift.TDeserializer;
@@ -56,7 +56,7 @@ public void write(Kryo kryo, Output output, TBase tBase) {
   }
 
   @Override
-  public TBase read(Kryo kryo, Input input, Class<TBase> tBaseClass) {
+  public TBase read(Kryo kryo, Input input, Class<? extends TBase> tBaseClass) {
     try {
       TBase prototype = tBaseClass.newInstance();
       int tSize = input.readInt(true);
diff --git a/project/CredPlugin.scala b/project/CredPlugin.scala
new file mode 100644
index 00000000..6b31c15b
--- /dev/null
+++ b/project/CredPlugin.scala
@@ -0,0 +1,23 @@
+import sbt.*
+import sbt.Keys.credentials
+
+object CredPlugin extends AutoPlugin {
+
+  override def trigger = allRequirements
+
+  override def buildSettings: Seq[Setting[_]] = {
+    val maybeCredentials =
+      (sys.env.get("NEXUS_HOST"), sys.env.get("NEXUS_USERNAME"), sys.env.get("NEXUS_PASSWORD")) match {
+        case (Some(host), Some(user), Some(password)) =>
+          Some(Credentials("Sonatype Nexus Repository Manager", host, user, password))
+        case _ =>
+          val credentialsFile = Path.userHome / ".sbt" / ".chill-credentials"
+          if (credentialsFile.exists()) {
+            Some(Credentials(credentialsFile))
+          } else {
+            None
+          }
+      }
+    maybeCredentials.fold(Seq.empty[Def.Setting[_]])(c => Seq(credentials += c))
+  }
+}
diff --git a/project/plugins.sbt b/project/plugins.sbt
index e634630e..7f9ed558 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -1,8 +1,10 @@
-addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "1.1.1")
-addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.9.3")
+//addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "1.1.1")
+addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.1.0")
 addSbtPlugin("org.scalameta" % "sbt-scalafmt" % "2.5.0")
-addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.10.4")
-addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.5.11")
+addSbtPlugin("ch.epfl.scala" % "sbt-scalafix" % "0.11.1")
+// https://github.com/sbt/sbt-dynver
+addSbtPlugin("com.github.sbt" % "sbt-dynver" % "5.0.1")
+//addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.5.12")
 addSbtPlugin("com.thesamet" % "sbt-protoc" % "1.0.6")
 
 libraryDependencies += "com.thesamet.scalapb" %% "compilerplugin" % "0.11.13"