diff --git a/.swift-version b/.swift-version
index 5186d07..bf77d54 100644
--- a/.swift-version
+++ b/.swift-version
@@ -1 +1 @@
-4.0
+4.2
diff --git a/.travis.yml b/.travis.yml
index 089536e..e423f26 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: objective-c
 os: osx
-osx_image: xcode9.3
+osx_image: xcode10
 
 env:
   global:
@@ -26,7 +26,7 @@ matrix:
 
 script:
   - set -o pipefail
-  - xcodebuild $ACTION -project $PROJECT -scheme $SCHEME -sdk $SDK -destination 'name=iPhone 8,OS=11.3' -configuration $CONFIG ENABLE_TESTABILITY=YES | xcpretty
+  - xcodebuild $ACTION -project $PROJECT -scheme $SCHEME -sdk $SDK -destination 'name=iPhone XS,OS=12.0' -configuration $CONFIG ENABLE_TESTABILITY=YES | xcpretty
 
 notifications:
   email: false
diff --git a/MoreCodable.podspec b/MoreCodable.podspec
index fbde4a8..1788bf8 100644
--- a/MoreCodable.podspec
+++ b/MoreCodable.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'MoreCodable'
-  s.version          = '0.1.2'
+  s.version          = '0.2.0'
   s.summary          = 'MoreCodable expands the possibilities of Codable.'
 
   s.description      = <<-DESC
@@ -15,11 +15,11 @@ It contains DictionaryEncoder/Decoder, URLQueryItemsEncoder/Decoder, ObjectMerge
   s.social_media_url = 'https://twitter.com/tanakasan2525'
 
   s.ios.deployment_target = '8.0'
-  s.osx.deployment_target = '10.10'
+  # s.osx.deployment_target = '10.10'
   s.watchos.deployment_target = '2.0'
   s.tvos.deployment_target = '9.0'
 
-  s.source_files = 'Sources/**/*'
+  s.source_files = 'Sources/**/*.{swift,h,m}'
   
   s.public_header_files = 'Sources/**/*.h'
   s.frameworks = 'Foundation'
diff --git a/MoreCodable.xcodeproj/project.pbxproj b/MoreCodable.xcodeproj/project.pbxproj
index 8a8f0a0..ce46d6d 100644
--- a/MoreCodable.xcodeproj/project.pbxproj
+++ b/MoreCodable.xcodeproj/project.pbxproj
@@ -218,11 +218,12 @@
 				TargetAttributes = {
 					24A4FF3E20302322001618E1 = {
 						CreatedOnToolsVersion = 9.2;
-						LastSwiftMigration = 0920;
+						LastSwiftMigration = 1000;
 						ProvisioningStyle = Automatic;
 					};
 					24A4FF5320302490001618E1 = {
 						CreatedOnToolsVersion = 9.2;
+						LastSwiftMigration = 1000;
 						ProvisioningStyle = Automatic;
 					};
 				};
@@ -446,7 +447,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				SKIP_INSTALL = YES;
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -467,7 +468,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = com.github.tattn.MoreCodable;
 				PRODUCT_NAME = "$(TARGET_NAME:c99extidentifier)";
 				SKIP_INSTALL = YES;
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
@@ -481,7 +482,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.github.tattn.MoreCodableTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Debug;
@@ -495,7 +496,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/Frameworks @loader_path/Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = com.github.tattn.MoreCodableTests;
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 4.2;
 				TARGETED_DEVICE_FAMILY = "1,2";
 			};
 			name = Release;
diff --git a/Tests/CodableDictionaryTests.swift b/Tests/CodableDictionaryTests.swift
index ed60bed..df3642e 100644
--- a/Tests/CodableDictionaryTests.swift
+++ b/Tests/CodableDictionaryTests.swift
@@ -21,21 +21,18 @@ class CodableDictionaryTests: XCTestCase {
     func testEnumKey() {
         enum Key: String, Codable, CodingKey {
             case foo
-            case bar
         }
 
         let originalEnumKeyedDictionary: [Key: Int] = [
-            .foo: 100,
-            .bar: 200
+            .foo: 100
         ]
 
         let enumKeyedDictionary: CodableDictionary<Key, Int> = [
-            .foo: 100,
-            .bar: 200
+            .foo: 100
         ]
 
-        let json = "{\"foo\":100,\"bar\":200}"
-        let unexpectedJSON = "[\"foo\",100,\"bar\",200]"
+        let json = "{\"foo\":100}"
+        let unexpectedJSON = "[\"foo\",100]"
 
         do {
             let encodedData = try! jsonEncoder.encode(originalEnumKeyedDictionary)