diff --git a/mobile/examples/java/hello_world/MainActivity.java b/mobile/examples/java/hello_world/MainActivity.java
index 5d1ebcd4ac55..d16842dac9f5 100644
--- a/mobile/examples/java/hello_world/MainActivity.java
+++ b/mobile/examples/java/hello_world/MainActivity.java
@@ -108,7 +108,8 @@ private void makeRequest() {
           String message = "received headers with status " + status;
 
           StringBuilder sb = new StringBuilder();
-          for (Map.Entry<String, List<String>> entry : responseHeaders.getHeaders().entrySet()) {
+          for (Map.Entry<String, List<String>> entry :
+               responseHeaders.caseSensitiveHeaders().entrySet()) {
             String name = entry.getKey();
             if (FILTERED_HEADERS.contains(name)) {
               sb.append(name).append(": ").append(String.join(", ", entry.getValue())).append("\n");
diff --git a/mobile/examples/kotlin/hello_world/MainActivity.kt b/mobile/examples/kotlin/hello_world/MainActivity.kt
index d58c7b40c133..f03f4c669bec 100644
--- a/mobile/examples/kotlin/hello_world/MainActivity.kt
+++ b/mobile/examples/kotlin/hello_world/MainActivity.kt
@@ -117,7 +117,7 @@ class MainActivity : Activity() {
         val message = "received headers with status $status"
 
         val sb = StringBuilder()
-        for ((name, value) in responseHeaders.headers) {
+        for ((name, value) in responseHeaders.caseSensitiveHeaders()) {
           if (name in FILTERED_HEADERS) {
             sb.append(name).append(": ").append(value.joinToString()).append("\n")
           }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/BUILD b/mobile/library/kotlin/io/envoyproxy/envoymobile/BUILD
index bda143dd19a7..e1435b528853 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/BUILD
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/BUILD
@@ -44,6 +44,7 @@ envoy_mobile_kt_library(
         "EnvoyError.kt",
         "Headers.kt",
         "HeadersBuilder.kt",
+        "HeadersContainer.kt",
         "KeyValueStore.kt",
         "LogLevel.kt",
         "PulseClient.kt",
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/Headers.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/Headers.kt
index 54b4de1e134a..a36dba772c35 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/Headers.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/Headers.kt
@@ -5,35 +5,37 @@ package io.envoyproxy.envoymobile
  * To instantiate new instances, see `{Request|Response}HeadersBuilder`.
  */
 open class Headers {
-  @Suppress("MemberNameEqualsClassName")
-  val headers: Map<String, List<String>>
+  val container: HeadersContainer
 
   /**
    * Internal constructor used by builders.
    *
-   * @param headers: Headers to set.
+   * @param container: The headers container to set.
    */
-  protected constructor(headers: Map<String, List<String>>) {
-    this.headers = headers
+  internal constructor(container: HeadersContainer) {
+    this.container = container
   }
 
   /**
-   * Get the value for the provided header name.
+   * Get the value for the provided header name. It's discouraged
+   * to use this dictionary for equality key-based lookups as this
+   * may lead to issues with headers that do not follow expected
+   * casing i.e., "Content-Length" instead of "content-length".
    *
    * @param name: Header name for which to get the current value.
    *
-   * @return List<String>?, The current headers specified for the provided name.
+   * @return The current headers specified for the provided name.
    */
   fun value(name: String): List<String>? {
-    return headers[name]
+    return container.value(name)
   }
 
   /**
    * Accessor for all underlying headers as a map.
    *
-   * @return Map<String, List<String>>, The underlying headers.
+   * @return The underlying headers.
    */
-  fun allHeaders(): Map<String, List<String>> {
-    return headers
+  fun caseSensitiveHeaders(): Map<String, List<String>> {
+    return container.caseSensitiveHeaders()
   }
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/HeadersBuilder.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/HeadersBuilder.kt
index 184b2885ac66..21906ad20a17 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/HeadersBuilder.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/HeadersBuilder.kt
@@ -5,15 +5,15 @@ package io.envoyproxy.envoymobile
  * See `{Request|Response}HeadersBuilder` for usage.
  */
 open class HeadersBuilder {
-  protected val headers: MutableMap<String, MutableList<String>>
+  protected val container: HeadersContainer
 
   /**
    * Instantiate a new builder, only used by child classes.
    *
-   * @param headers: The headers to start with.
+   * @param container: The headers container to start with.
    */
-  protected constructor(headers: MutableMap<String, MutableList<String>>) {
-    this.headers = headers
+  internal constructor(container: HeadersContainer) {
+    this.container = container
   }
 
   /**
@@ -28,7 +28,7 @@ open class HeadersBuilder {
     if (isRestrictedHeader(name)) {
       return this
     }
-    headers.getOrPut(name) { mutableListOf<String>() }.add(value)
+    container.add(name, value)
     return this
   }
 
@@ -44,7 +44,7 @@ open class HeadersBuilder {
     if (isRestrictedHeader(name)) {
       return this
     }
-    headers[name] = value
+    container.set(name, value)
     return this
   }
 
@@ -59,7 +59,7 @@ open class HeadersBuilder {
     if (isRestrictedHeader(name)) {
       return this
     }
-    headers.remove(name)
+    container.remove(name)
     return this
   }
 
@@ -72,10 +72,10 @@ open class HeadersBuilder {
    * @return HeadersBuilder, This builder.
    */
   internal open fun internalSet(name: String, value: MutableList<String>): HeadersBuilder {
-    headers[name] = value
+    container.set(name, value)
     return this
   }
 
   private fun isRestrictedHeader(name: String) = name.startsWith(":") ||
-    name.startsWith("x-envoy-mobile") || name == "host"
+    name.startsWith("x-envoy-mobile", ignoreCase = true) || name.equals("host", ignoreCase = true)
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/HeadersContainer.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/HeadersContainer.kt
new file mode 100644
index 000000000000..ae93e631843c
--- /dev/null
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/HeadersContainer.kt
@@ -0,0 +1,135 @@
+package io.envoyproxy.envoymobile
+
+/**
+ * The container that manages the underlying headers map.
+ * It maintains the original casing of passed header names.
+ * It treats headers names as case-insensitive for the purpose
+ * of header lookups and header name conflict resolutions.
+ */
+open class HeadersContainer {
+  protected val headers: MutableMap<String, Header>
+
+  /**
+   * Represents a header name together with all of its values.
+   * It preserves the original casing of the header name.
+   */
+  data class Header(val name: String, var value: MutableList<String>) {
+    constructor(name: String) : this(name, mutableListOf())
+
+    fun add(value: List<String>) {
+      this.value.addAll(value)
+    }
+
+    fun add(value: String) {
+      this.value.add(value)
+    }
+  }
+
+  /**
+   * Instantiate a new instance of the receiver using the provided headers map
+   *
+   * @param headers: The headers to start with.
+   */
+  internal constructor(headers: Map<String, MutableList<String>>) {
+    var underlyingHeaders = mutableMapOf<String, Header>()
+    /**
+     * Dictionaries are unordered collections. Process headers with names
+     * that are the same when lowercased in an alphabetical order to avoid a situation
+     * in which the result of the initialization is non-derministic i.e., we want
+     * mapOf("A" to listOf("1"), "a" to listOf("2")) headers to be always converted to
+     * mapOf("A" to listOf("1", "2")) and never to mapOf("a" to listOf("2", "1")).
+     *
+     * If a given header name already exists in the processed headers map, check
+     * if the currently processed header name is before the existing header name as
+     * determined by an alphabetical order.
+     */
+    headers.forEach {
+      val lowercased = it.key.lowercase()
+      val existing = underlyingHeaders[lowercased]
+
+      if (existing == null) {
+        underlyingHeaders[lowercased] = Header(it.key, it.value)
+      } else if (existing.name > it.key) {
+        underlyingHeaders[lowercased] = Header(it.key, (it.value + existing.value).toMutableList())
+      } else {
+        underlyingHeaders[lowercased]?.add(it.value)
+      }
+    }
+
+    this.headers = underlyingHeaders
+  }
+
+  companion object {
+    /**
+     * Create a new instance of the receiver using a provider headers map.
+     * Not implemented as a constructor due to conflicting JVM signatures with
+     * other constructors.
+     *
+     * @param headers: The headers to create the container with.
+     */
+    fun create(headers: Map<String, List<String>>) : HeadersContainer {
+      return HeadersContainer(headers.mapValues { it.value.toMutableList() })
+    }
+  }
+
+  /**
+   * Add a value to a header with a given name.
+   *
+   * @param name  The name of the header. For the purpose of headers lookup
+   *              and header name conflict resolution, the name of the header
+   *              is considered to be case-insensitive.
+   * @param value The value to add.
+   */
+  fun add(name: String, value: String) {
+    val lowercased = name.lowercase()
+    headers[lowercased]?.let { it.add(value) } ?: run {
+      headers.put(lowercased, Header(name, mutableListOf(value)))
+    }
+  }
+
+
+  /**
+   * Set the value of a given header.
+   *
+   * @param name  The name of the header.
+   * @param value The value to set the header value to.
+   */
+  fun set(name: String, value: List<String>) {
+    headers[name.lowercase()] = Header(name, value.toMutableList())
+  }
+
+  /**
+   * Remove a given header.
+   *
+   * @param name The name of the header to remove.
+   */
+  fun remove(name: String) {
+    headers.remove(name.lowercase())
+  }
+
+  /**
+   * Get the value for the provided header name.
+   *
+   * @param name The case-insensitive header name for which to
+   *             get the current value.
+   * @return The value associated with a given header.
+   */
+  fun value(name: String): List<String>? {
+    return headers[name.lowercase()]?.value
+  }
+
+  /**
+   * Accessor for all underlying case-sensitive headers. When possible,
+   * use case-insensitive accessors instead.
+   *
+   * @return The underlying headers.
+   */
+  fun caseSensitiveHeaders(): Map<String, List<String>> {
+    var caseSensitiveHeaders = mutableMapOf<String, List<String>>()
+    headers.forEach {
+      caseSensitiveHeaders.put(it.value.name, it.value.value)
+    }
+
+    return caseSensitiveHeaders
+  }
+}
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestHeaders.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestHeaders.kt
index aa27080facc6..5c0c33da7d57 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestHeaders.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestHeaders.kt
@@ -9,7 +9,9 @@ open class RequestHeaders : Headers {
    *
    * @param headers: Headers to set.
    */
-  internal constructor(headers: Map<String, List<String>>) : super(headers)
+  internal constructor(headers: Map<String, List<String>>) : super(HeadersContainer.create(headers))
+
+  internal constructor(container: HeadersContainer): super(container)
 
   /**
    * Method for the request.
@@ -49,9 +51,5 @@ open class RequestHeaders : Headers {
    *
    * @return RequestHeadersBuilder, The new builder.
    */
-  fun toRequestHeadersBuilder() = RequestHeadersBuilder(
-    headers.mapValues {
-      it.value.toMutableList()
-    }.toMutableMap()
-  )
+  fun toRequestHeadersBuilder() = RequestHeadersBuilder(container)
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestHeadersBuilder.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestHeadersBuilder.kt
index 0e5450c97547..ffe75da9d813 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestHeadersBuilder.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestHeadersBuilder.kt
@@ -18,14 +18,15 @@ class RequestHeadersBuilder : HeadersBuilder {
     authority: String,
     path: String
   ) :
-    super(
-      mutableMapOf(
+    super(HeadersContainer(
+      mapOf(
         ":authority" to mutableListOf(authority),
         ":method" to mutableListOf(method.stringValue),
         ":path" to mutableListOf(path),
         ":scheme" to mutableListOf(scheme)
       )
     )
+    )
 
   /**
    * Instantiate a new builder. Used only by RequestHeaders to convert back to
@@ -33,7 +34,14 @@ class RequestHeadersBuilder : HeadersBuilder {
    *
    * @param headers: The headers to start with.
    */
-  internal constructor(headers: MutableMap<String, MutableList<String>>) : super(headers)
+  internal constructor(headers: Map<String, MutableList<String>>) : super(HeadersContainer(headers))
+
+  /**
+   * Instantiate a new builder.
+   *
+   * @param container: The headers container to start with.
+   */
+  internal constructor(container: HeadersContainer) : super(container)
 
   override fun add(name: String, value: String): RequestHeadersBuilder {
     super.add(name, value)
@@ -92,6 +100,6 @@ class RequestHeadersBuilder : HeadersBuilder {
    * @return RequestHeaders, New instance of request headers.
    */
   fun build(): RequestHeaders {
-    return RequestHeaders(headers)
+    return RequestHeaders(container)
   }
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestTrailers.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestTrailers.kt
index ed7d973618db..1254a1e62b30 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestTrailers.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestTrailers.kt
@@ -12,14 +12,17 @@ class RequestTrailers : Trailers {
    */
   internal constructor(trailers: Map<String, List<String>>) : super(trailers)
 
+  /**
+   * Instantiate a new builder.
+   *
+   * @param container: The headers container to start with.
+   */
+  internal constructor(container: HeadersContainer) : super(container)
+
   /**
    * Convert the trailers back to a builder for mutation.
    *
    * @return RequestTrailersBuilder, The new builder.
    */
-  fun toRequestTrailersBuilder() = RequestTrailersBuilder(
-    headers.mapValues {
-      it.value.toMutableList()
-    }.toMutableMap()
-  )
+  fun toRequestTrailersBuilder() = RequestTrailersBuilder(container)
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestTrailersBuilder.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestTrailersBuilder.kt
index fc82d15fb929..b701bb6e89f1 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestTrailersBuilder.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/RequestTrailersBuilder.kt
@@ -4,18 +4,26 @@ package io.envoyproxy.envoymobile
  * Builder used for constructing instances of `RequestTrailers`.
  */
 class RequestTrailersBuilder : HeadersBuilder {
-  /**
-   * Initialize a new instance of the builder.
+  /*
+   * Instantiate a new builder.
    */
-  constructor() : super(mutableMapOf())
+  internal constructor() : super(HeadersContainer(mapOf()))
 
-  /**
+  /*
+   * Instantiate a new instance of the builder.
+   *
+   * @param container: The headers container to start with.
+   */
+  internal constructor(container: HeadersContainer) : super(container)
+
+  /*
    * Instantiate a new builder. Used only by RequestTrailers to convert back to
    * RequestTrailersBuilder.
    *
    * @param trailers: The trailers to start with.
    */
-  internal constructor(trailers: MutableMap<String, MutableList<String>>) : super(trailers)
+  internal constructor(trailers: MutableMap<String, MutableList<String>>)
+    : super(HeadersContainer(trailers))
 
   override fun add(name: String, value: String): RequestTrailersBuilder {
     super.add(name, value)
@@ -43,6 +51,6 @@ class RequestTrailersBuilder : HeadersBuilder {
    * @return RequestTrailers, New instance of request trailers.
    */
   fun build(): RequestTrailers {
-    return RequestTrailers(headers)
+    return RequestTrailers(container)
   }
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseHeaders.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseHeaders.kt
index 65557038931b..dbfdd8e383f8 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseHeaders.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseHeaders.kt
@@ -9,7 +9,9 @@ class ResponseHeaders : Headers {
    *
    * @param headers: Headers to set.
    */
-  internal constructor(headers: Map<String, List<String>>) : super(headers)
+  internal constructor(headers: Map<String, List<String>>) : super(HeadersContainer.create(headers))
+
+  internal constructor(container: HeadersContainer) : super(container)
 
   /**
    * HTTP status code received with the response.
@@ -23,9 +25,5 @@ class ResponseHeaders : Headers {
    *
    * @return ResponseHeadersBuilder, The new builder.
    */
-  fun toResponseHeadersBuilder() = ResponseHeadersBuilder(
-    headers.mapValues {
-      it.value.toMutableList()
-    }.toMutableMap()
-  )
+  fun toResponseHeadersBuilder() = ResponseHeadersBuilder(container)
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseHeadersBuilder.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseHeadersBuilder.kt
index 81c744d50fdb..7b47675eaeef 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseHeadersBuilder.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseHeadersBuilder.kt
@@ -5,18 +5,26 @@ package io.envoyproxy.envoymobile
  */
 class ResponseHeadersBuilder : HeadersBuilder {
 
-  /**
-   * Initialize a new instance of the builder.
+  /*
+   * Instantiate a new builder.
    */
-  constructor() : super(mutableMapOf())
+  internal constructor() : super(HeadersContainer(mapOf()))
 
-  /**
+  /*
    * Instantiate a new builder. Used only by ResponseHeaders to convert back to
    * ResponseHeadersBuilder.
    *
    * @param headers: The headers to start with.
    */
-  internal constructor(headers: MutableMap<String, MutableList<String>>) : super(headers)
+  internal constructor(headers: MutableMap<String, MutableList<String>>)
+    : super(HeadersContainer(headers))
+
+  /*
+   * Instantiate a new builder.
+   *
+   * @param container: The headers container to start with.
+   */
+  internal constructor(container: HeadersContainer) : super(container)
 
   override fun add(name: String, value: String): ResponseHeadersBuilder {
     super.add(name, value)
@@ -59,6 +67,6 @@ class ResponseHeadersBuilder : HeadersBuilder {
    * @return ResponseHeaders, New instance of response headers.
    */
   fun build(): ResponseHeaders {
-    return ResponseHeaders(headers)
+    return ResponseHeaders(container)
   }
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseTrailers.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseTrailers.kt
index a51c10059b55..c61f71dcac85 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseTrailers.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseTrailers.kt
@@ -12,14 +12,17 @@ class ResponseTrailers : Trailers {
    */
   internal constructor(trailers: Map<String, List<String>>) : super(trailers)
 
+  /**
+   * Instantiate a new builder.
+   *
+   * @param container: The headers container to start with.
+   */
+  internal constructor(container: HeadersContainer) : super(container)
+
   /**
    * Convert the trailers back to a builder for mutation.
    *
    * @return ResponseTrailersBuilder, The new builder.
    */
-  fun toResponseTrailersBuilder() = ResponseTrailersBuilder(
-    headers.mapValues {
-      it.value.toMutableList()
-    }.toMutableMap()
-  )
+  fun toResponseTrailersBuilder() = ResponseTrailersBuilder(container)
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseTrailersBuilder.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseTrailersBuilder.kt
index ad97289373ef..0e21ce27d457 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseTrailersBuilder.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/ResponseTrailersBuilder.kt
@@ -7,7 +7,7 @@ class ResponseTrailersBuilder : HeadersBuilder {
   /**
    * Initialize a new instance of the builder.
    */
-  constructor() : super(mutableMapOf())
+  constructor() : super(HeadersContainer(mapOf()))
 
   /**
    * Instantiate a new builder. Used only by ResponseTrailers to convert back to
@@ -15,7 +15,10 @@ class ResponseTrailersBuilder : HeadersBuilder {
    *
    * @param trailers: The trailers to start with.
    */
-  internal constructor(trailers: MutableMap<String, MutableList<String>>) : super(trailers)
+  internal constructor(trailers: MutableMap<String, MutableList<String>>)
+    : super(HeadersContainer(trailers))
+
+  internal constructor(container: HeadersContainer) : super(container)
 
   override fun add(name: String, value: String): ResponseTrailersBuilder {
     super.add(name, value)
@@ -43,6 +46,6 @@ class ResponseTrailersBuilder : HeadersBuilder {
    * @return ResponseTrailers, New instance of response trailers.
    */
   fun build(): ResponseTrailers {
-    return ResponseTrailers(headers)
+    return ResponseTrailers(container)
   }
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/Stream.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/Stream.kt
index b51fe23b6a89..5c86dc26580b 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/Stream.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/Stream.kt
@@ -20,7 +20,7 @@ open class Stream(
    * @return This stream, for chaining syntax.
    */
   open fun sendHeaders(headers: RequestHeaders, endStream: Boolean): Stream {
-    underlyingStream.sendHeaders(headers.allHeaders(), endStream)
+    underlyingStream.sendHeaders(headers.caseSensitiveHeaders(), endStream)
     return this
   }
 
@@ -58,7 +58,7 @@ open class Stream(
    * @param trailers Trailers with which to close the stream.
    */
   open fun close(trailers: RequestTrailers) {
-    underlyingStream.sendTrailers(trailers.allHeaders())
+    underlyingStream.sendTrailers(trailers.caseSensitiveHeaders())
   }
 
   /**
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/Trailers.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/Trailers.kt
index ef7f7b2481f8..6e806ce9b39b 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/Trailers.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/Trailers.kt
@@ -10,5 +10,8 @@ open class Trailers : Headers {
    *
    * @param trailers: Trailers to set.
    */
-  protected constructor(trailers: Map<String, List<String>>) : super(trailers)
+  protected constructor(trailers: Map<String, List<String>>)
+    : super(HeadersContainer.create(trailers))
+
+  protected constructor(container: HeadersContainer) : super(container)
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/filters/Filter.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/filters/Filter.kt
index d83845ff94df..ba9d419e2928 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/filters/Filter.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/filters/Filter.kt
@@ -32,7 +32,7 @@ internal class EnvoyHTTPFilterAdapter(
     (filter as? RequestFilter)?.let { requestFilter ->
       val result = requestFilter.onRequestHeaders(RequestHeaders(headers), endStream, StreamIntel(streamIntel))
       return when (result) {
-        is FilterHeadersStatus.Continue -> arrayOf(result.status, result.headers.headers)
+        is FilterHeadersStatus.Continue -> arrayOf(result.status, result.headers.caseSensitiveHeaders())
         is FilterHeadersStatus.StopIteration -> arrayOf(result.status, emptyMap<String, List<String>>())
       }
     }
@@ -43,7 +43,7 @@ internal class EnvoyHTTPFilterAdapter(
     (filter as? ResponseFilter)?.let { responseFilter ->
       val result = responseFilter.onResponseHeaders(ResponseHeaders(headers), endStream, StreamIntel(streamIntel))
       return when (result) {
-        is FilterHeadersStatus.Continue -> arrayOf(result.status, result.headers.headers)
+        is FilterHeadersStatus.Continue -> arrayOf(result.status, result.headers.caseSensitiveHeaders())
         is FilterHeadersStatus.StopIteration -> arrayOf(result.status, emptyMap<String, List<String>>())
       }
     }
@@ -57,7 +57,7 @@ internal class EnvoyHTTPFilterAdapter(
         is FilterDataStatus.Continue<*> -> arrayOf(result.status, result.data)
         is FilterDataStatus.StopIterationAndBuffer<*> -> arrayOf(result.status, ByteBuffer.allocate(0))
         is FilterDataStatus.StopIterationNoBuffer<*> -> arrayOf(result.status, ByteBuffer.allocate(0))
-        is FilterDataStatus.ResumeIteration<*> -> arrayOf(result.status, result.data, result.headers?.headers)
+        is FilterDataStatus.ResumeIteration<*> -> arrayOf(result.status, result.data, result.headers?.caseSensitiveHeaders())
       }
     }
     return arrayOf(0, data)
@@ -70,7 +70,7 @@ internal class EnvoyHTTPFilterAdapter(
         is FilterDataStatus.Continue<*> -> arrayOf(result.status, result.data)
         is FilterDataStatus.StopIterationAndBuffer<*> -> arrayOf(result.status, ByteBuffer.allocate(0))
         is FilterDataStatus.StopIterationNoBuffer<*> -> arrayOf(result.status, ByteBuffer.allocate(0))
-        is FilterDataStatus.ResumeIteration<*> -> arrayOf(result.status, result.data, result.headers?.headers)
+        is FilterDataStatus.ResumeIteration<*> -> arrayOf(result.status, result.data, result.headers?.caseSensitiveHeaders())
       }
     }
     return arrayOf(0, data)
@@ -80,9 +80,9 @@ internal class EnvoyHTTPFilterAdapter(
     (filter as? RequestFilter)?.let { requestFilter ->
       val result = requestFilter.onRequestTrailers(RequestTrailers(trailers), StreamIntel(streamIntel))
       return when (result) {
-        is FilterTrailersStatus.Continue<*, *> -> arrayOf(result.status, result.trailers.headers)
+        is FilterTrailersStatus.Continue<*, *> -> arrayOf(result.status, result.trailers.caseSensitiveHeaders())
         is FilterTrailersStatus.StopIteration<*, *> -> arrayOf(result.status, emptyMap<String, List<String>>())
-        is FilterTrailersStatus.ResumeIteration<*, *> -> arrayOf(result.status, result.trailers.headers, result.headers?.headers, result.data)
+        is FilterTrailersStatus.ResumeIteration<*, *> -> arrayOf(result.status, result.trailers.caseSensitiveHeaders(), result.headers?.caseSensitiveHeaders(), result.data)
       }
     }
     return arrayOf(0, trailers)
@@ -92,9 +92,9 @@ internal class EnvoyHTTPFilterAdapter(
     (filter as? ResponseFilter)?.let { responseFilter ->
       val result = responseFilter.onResponseTrailers(ResponseTrailers(trailers), StreamIntel(streamIntel))
       return when (result) {
-        is FilterTrailersStatus.Continue<*, *> -> arrayOf(result.status, result.trailers.headers)
+        is FilterTrailersStatus.Continue<*, *> -> arrayOf(result.status, result.trailers.caseSensitiveHeaders())
         is FilterTrailersStatus.StopIteration<*, *> -> arrayOf(result.status, emptyMap<String, List<String>>())
-        is FilterTrailersStatus.ResumeIteration<*, *> -> arrayOf(result.status, result.trailers.headers, result.headers?.headers, result.data)
+        is FilterTrailersStatus.ResumeIteration<*, *> -> arrayOf(result.status, result.trailers.caseSensitiveHeaders(), result.headers?.caseSensitiveHeaders(), result.data)
       }
     }
     return arrayOf(0, trailers)
@@ -134,7 +134,7 @@ internal class EnvoyHTTPFilterAdapter(
         StreamIntel(streamIntel)
       )
       return when (result) {
-        is FilterResumeStatus.ResumeIteration<*, *> -> arrayOf(result.status, result.headers?.headers, result.data, result.trailers?.headers)
+        is FilterResumeStatus.ResumeIteration<*, *> -> arrayOf(result.status, result.headers?.caseSensitiveHeaders(), result.data, result.trailers?.caseSensitiveHeaders())
       }
     }
     return arrayOf(-1, headers, data, trailers)
@@ -156,7 +156,7 @@ internal class EnvoyHTTPFilterAdapter(
         StreamIntel(streamIntel)
       )
       return when (result) {
-        is FilterResumeStatus.ResumeIteration<*, *> -> arrayOf(result.status, result.headers?.headers, result.data, result.trailers?.headers)
+        is FilterResumeStatus.ResumeIteration<*, *> -> arrayOf(result.status, result.headers?.caseSensitiveHeaders(), result.data, result.trailers?.caseSensitiveHeaders())
       }
     }
     return arrayOf(-1, headers, data, trailers)
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/grpc/GRPCRequestHeaders.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/grpc/GRPCRequestHeaders.kt
index 119ee4aff8ae..faacfa08477a 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/grpc/GRPCRequestHeaders.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/grpc/GRPCRequestHeaders.kt
@@ -9,16 +9,14 @@ class GRPCRequestHeaders : RequestHeaders {
    *
    * @param headers: Headers to set.
    */
-  internal constructor(headers: Map<String, List<String>>) : super(headers)
+  internal constructor(headers: Map<String, MutableList<String>>) : super(HeadersContainer(headers))
+
+  internal constructor(container: HeadersContainer) : super(container)
 
   /**
    * Convert the headers back to a builder for mutation.
    *
    * @return GRPCRequestHeadersBuilder, The new builder.
    */
-  fun toGRPCRequestHeadersBuilder() = GRPCRequestHeadersBuilder(
-    headers.mapValues {
-      it.value.toMutableList()
-    }.toMutableMap()
-  )
+  fun toGRPCRequestHeadersBuilder() = GRPCRequestHeadersBuilder(container)
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/grpc/GRPCRequestHeadersBuilder.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/grpc/GRPCRequestHeadersBuilder.kt
index 38c20b08e93c..d94721005802 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/grpc/GRPCRequestHeadersBuilder.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/grpc/GRPCRequestHeadersBuilder.kt
@@ -9,7 +9,14 @@ class GRPCRequestHeadersBuilder : HeadersBuilder {
    *
    * @param headers: Headers to set.
    */
-  internal constructor(headers: MutableMap<String, MutableList<String>>) : super(headers)
+  internal constructor(headers: Map<String, MutableList<String>>) : super(HeadersContainer(headers))
+
+  /**
+   * Instantiate a new builder.
+   *
+   * @param container: The headers container to start with.
+   */
+  internal constructor(container: HeadersContainer) : super(container)
 
   override fun add(name: String, value: String): GRPCRequestHeadersBuilder {
     super.add(name, value)
@@ -38,8 +45,8 @@ class GRPCRequestHeadersBuilder : HeadersBuilder {
    * @param authority The URL authority for the request (i.e., "api.foo.com").
    * @param path Path for the RPC (i.e., `/pb.api.v1.Foo/GetBar`).
    */
-  constructor(scheme: String, authority: String, path: String) : super(
-    mutableMapOf<String, MutableList<String>>(
+  constructor(scheme: String, authority: String, path: String) : super(HeadersContainer(
+    mapOf<String, MutableList<String>>(
       ":authority" to mutableListOf<String>(authority),
       ":method" to mutableListOf<String>("POST"),
       ":path" to mutableListOf<String>(path),
@@ -48,6 +55,7 @@ class GRPCRequestHeadersBuilder : HeadersBuilder {
       "x-envoy-mobile-upstream-protocol" to mutableListOf<String>(UpstreamHttpProtocol.HTTP2.stringValue)
     )
   )
+  )
 
   /**
    * Add a specific timeout for the gRPC request. This will be sent in the `grpc-timeout` header.
@@ -71,6 +79,6 @@ class GRPCRequestHeadersBuilder : HeadersBuilder {
    * @return New instance of request headers.
    */
   fun build(): GRPCRequestHeaders {
-    return GRPCRequestHeaders(headers)
+    return GRPCRequestHeaders(container)
   }
 }
diff --git a/mobile/library/kotlin/io/envoyproxy/envoymobile/mocks/MockStream.kt b/mobile/library/kotlin/io/envoyproxy/envoymobile/mocks/MockStream.kt
index 8bdb28460318..ef52df579a30 100644
--- a/mobile/library/kotlin/io/envoyproxy/envoymobile/mocks/MockStream.kt
+++ b/mobile/library/kotlin/io/envoyproxy/envoymobile/mocks/MockStream.kt
@@ -81,7 +81,7 @@ class MockStream internal constructor(underlyingStream: MockEnvoyHTTPStream) : S
    * @param endStream Whether this is a headers-only response.
    */
   fun receiveHeaders(headers: ResponseHeaders, endStream: Boolean) {
-    mockStream.callbacks.onHeaders(headers.allHeaders(), endStream, mockStreamIntel)
+    mockStream.callbacks.onHeaders(headers.caseSensitiveHeaders(), endStream, mockStreamIntel)
   }
 
   /**
@@ -100,7 +100,7 @@ class MockStream internal constructor(underlyingStream: MockEnvoyHTTPStream) : S
    * @param trailers Response trailers to receive.
    */
   fun receiveTrailers(trailers: ResponseTrailers) {
-    mockStream.callbacks.onTrailers(trailers.allHeaders(), mockStreamIntel)
+    mockStream.callbacks.onTrailers(trailers.caseSensitiveHeaders(), mockStreamIntel)
   }
 
   /**
diff --git a/mobile/library/swift/Headers.swift b/mobile/library/swift/Headers.swift
index 779b57b940b0..cc477b0310d0 100644
--- a/mobile/library/swift/Headers.swift
+++ b/mobile/library/swift/Headers.swift
@@ -27,7 +27,7 @@ public class Headers: NSObject {
   ///
   /// - returns: The underlying case-sensitive headers.
   public func caseSensitiveHeaders() -> [String: [String]] {
-    return self.container.allHeaders()
+    return self.container.caseSensitiveHeaders()
   }
 
   /// Internal initializer used by builders.
diff --git a/mobile/library/swift/HeadersBuilder.swift b/mobile/library/swift/HeadersBuilder.swift
index b245f3aee55d..787a790e259d 100644
--- a/mobile/library/swift/HeadersBuilder.swift
+++ b/mobile/library/swift/HeadersBuilder.swift
@@ -60,7 +60,7 @@ public class HeadersBuilder: NSObject {
       return self
     }
 
-    self.container.set(name: name, value: nil)
+    self.container.remove(name: name)
     return self
   }
 
@@ -78,8 +78,12 @@ public class HeadersBuilder: NSObject {
     return self
   }
 
-  func allHeaders() -> [String: [String]] {
-    return self.container.allHeaders()
+  /// Accessor for all underlying case-sensitive headers. When possible,
+  /// use case-insensitive accessors instead.
+  ///
+  /// - returns: The underlying case-sensitive headers.
+  func caseSensitiveHeaders() -> [String: [String]] {
+    return self.container.caseSensitiveHeaders()
   }
 
   // Only explicitly implemented to work around a swiftinterface issue in Swift 5.1. This can be
diff --git a/mobile/library/swift/HeadersContainer.swift b/mobile/library/swift/HeadersContainer.swift
index 2f2e63134857..678b6ae4ce24 100644
--- a/mobile/library/swift/HeadersContainer.swift
+++ b/mobile/library/swift/HeadersContainer.swift
@@ -1,11 +1,11 @@
-/// The container which manages the underlying headers map.
+/// The container that manages the underlying headers map.
 /// It maintains the original casing of passed header names.
 /// It treats headers names as case-insensitive for the purpose
 /// of header lookups and header name conflict resolutions.
 struct HeadersContainer: Equatable {
   private var headers: [String: Header]
 
-  /// Represents a headers name together with all of its values.
+  /// Represents a header name together with all of its values.
   /// It preserves the original casing of the header name.
   struct Header: Equatable {
     private(set) var name: String
@@ -32,10 +32,10 @@ struct HeadersContainer: Equatable {
     var underlyingHeaders = [String: Header]()
     for (name, value) in headers {
       let lowercasedName = name.lowercased()
-      /// Dictionaries in Swift are unordered collections. Process headers with names
+      /// Dictionaries are unordered collections. Process headers with names
       /// that are the same when lowercased in an alphabetical order to avoid a situation
       /// in which the result of the initialization is non-derministic i.e., we want
-      /// "[A: ["1"]", "a: ["2"]]" headers to be always converted to ["A": ["1", "2"]] and
+      /// ["A": ["1"], "a": ["2"]] headers to be always converted to ["A": ["1", "2"]] and
       /// never to "a": ["2", "1"].
       ///
       /// If a given header name already exists in the processed headers map, check
@@ -75,14 +75,17 @@ struct HeadersContainer: Equatable {
   ///
   /// - parameter name:  The name of the header.
   /// - parameter value: The value to set the header value to.
-  mutating func set(name: String, value: [String]?) {
-    guard let value = value else {
-      self.headers[name.lowercased()] = nil
-      return
-    }
+  mutating func set(name: String, value: [String]) {
     self.headers[name.lowercased()] = Header(name: name, value: value)
   }
 
+  /// Remove a given header.
+  ///
+  /// - parameter name: The name of the header to remove.
+  mutating func remove(name: String) {
+    self.headers[name.lowercased()] = nil
+  }
+
   /// Get the value for the provided header name.
   ///
   /// - parameter name: The case-insensitive header name for which to
@@ -93,10 +96,11 @@ struct HeadersContainer: Equatable {
     return self.headers[name.lowercased()]?.value
   }
 
-  /// Return all underlying headers.
+  /// Accessor for all underlying case-sensitive headers. When possible,
+  /// use case-insensitive accessors instead.
   ///
   /// - returns: The underlying headers.
-  func allHeaders() -> [String: [String]] {
+  func caseSensitiveHeaders() -> [String: [String]] {
     return Dictionary(uniqueKeysWithValues: self.headers.map { _, value in
       return (value.name, value.value)
     })
diff --git a/mobile/test/kotlin/apps/baseline/MainActivity.kt b/mobile/test/kotlin/apps/baseline/MainActivity.kt
index e66aab379368..9e38852b70f6 100644
--- a/mobile/test/kotlin/apps/baseline/MainActivity.kt
+++ b/mobile/test/kotlin/apps/baseline/MainActivity.kt
@@ -116,7 +116,7 @@ class MainActivity : Activity() {
         val message = "received headers with status $status"
 
         val sb = StringBuilder()
-        for ((name, value) in responseHeaders.headers) {
+        for ((name, value) in responseHeaders.caseSensitiveHeaders()) {
           if (name in FILTERED_HEADERS) {
             sb.append(name).append(": ").append(value.joinToString()).append("\n")
           }
diff --git a/mobile/test/kotlin/apps/experimental/MainActivity.kt b/mobile/test/kotlin/apps/experimental/MainActivity.kt
index 45dd82fee484..704d4b34b6f3 100644
--- a/mobile/test/kotlin/apps/experimental/MainActivity.kt
+++ b/mobile/test/kotlin/apps/experimental/MainActivity.kt
@@ -125,7 +125,7 @@ class MainActivity : Activity() {
         val message = "received headers with status $status"
 
         val sb = StringBuilder()
-        for ((name, value) in responseHeaders.headers) {
+        for ((name, value) in responseHeaders.caseSensitiveHeaders()) {
           if (name in FILTERED_HEADERS) {
             sb.append(name).append(": ").append(value.joinToString()).append("\n")
           }
diff --git a/mobile/test/kotlin/io/envoyproxy/envoymobile/BUILD b/mobile/test/kotlin/io/envoyproxy/envoymobile/BUILD
index 7140a39e9b50..218fa13fa8f2 100644
--- a/mobile/test/kotlin/io/envoyproxy/envoymobile/BUILD
+++ b/mobile/test/kotlin/io/envoyproxy/envoymobile/BUILD
@@ -99,3 +99,13 @@ envoy_mobile_kt_test(
         "//library/kotlin/io/envoyproxy/envoymobile:envoy_interfaces_lib",
     ],
 )
+
+envoy_mobile_kt_test(
+    name = "headers_container_test",
+    srcs = [
+        "HeadersContainerTest.kt",
+    ],
+    deps = [
+        "//library/kotlin/io/envoyproxy/envoymobile:envoy_interfaces_lib",
+    ],
+)
diff --git a/mobile/test/kotlin/io/envoyproxy/envoymobile/GRPCStreamTest.kt b/mobile/test/kotlin/io/envoyproxy/envoymobile/GRPCStreamTest.kt
index fa3b701fdcec..c0bd2d34ea4f 100644
--- a/mobile/test/kotlin/io/envoyproxy/envoymobile/GRPCStreamTest.kt
+++ b/mobile/test/kotlin/io/envoyproxy/envoymobile/GRPCStreamTest.kt
@@ -104,7 +104,7 @@ class GRPCStreamTest {
     GRPCClient(streamClient)
       .newGRPCStreamPrototype()
       .setOnResponseHeaders { headers, endStream, _ ->
-        assertThat(headers.allHeaders()).isEqualTo(expectedHeaders.allHeaders())
+        assertThat(headers.caseSensitiveHeaders()).isEqualTo(expectedHeaders.caseSensitiveHeaders())
         assertThat(endStream).isTrue()
         countDownLatch.countDown()
       }
@@ -124,7 +124,7 @@ class GRPCStreamTest {
     GRPCClient(streamClient)
       .newGRPCStreamPrototype()
       .setOnResponseTrailers { trailers, _ ->
-        assertThat(trailers.allHeaders()).isEqualTo(expectedTrailers.allHeaders())
+        assertThat(trailers.caseSensitiveHeaders()).isEqualTo(expectedTrailers.caseSensitiveHeaders())
         countDownLatch.countDown()
       }
       .start(Executor {})
diff --git a/mobile/test/kotlin/io/envoyproxy/envoymobile/HeadersBuilderTest.kt b/mobile/test/kotlin/io/envoyproxy/envoymobile/HeadersBuilderTest.kt
index de5810f01af3..0035008f94c7 100644
--- a/mobile/test/kotlin/io/envoyproxy/envoymobile/HeadersBuilderTest.kt
+++ b/mobile/test/kotlin/io/envoyproxy/envoymobile/HeadersBuilderTest.kt
@@ -13,6 +13,15 @@ class HeadersBuilderTest {
     assertThat(headers.value("x-foo")).containsExactly("1", "2")
   }
 
+  @Test
+  fun `adding header performs a case-insensitive header name lookup`() {
+    val headers = RequestHeadersBuilder(mutableMapOf())
+      .add("fOo", "abc")
+      .add("foo", "123")
+      .build()
+    assertThat(headers.caseSensitiveHeaders()).isEqualTo(mapOf("fOo" to listOf("abc", "123")))
+  }
+
   @Test
   fun `removing specific header key removes all of its values`() {
     val headers = RequestHeadersBuilder(mutableMapOf())
@@ -20,8 +29,7 @@ class HeadersBuilderTest {
       .add("x-foo", "2")
       .remove("x-foo")
       .build()
-
-    assertThat(headers.allHeaders()).doesNotContainKey("x-foo")
+    assertThat(headers.caseSensitiveHeaders()).doesNotContainKey("x-foo")
   }
 
   @Test
@@ -34,6 +42,15 @@ class HeadersBuilderTest {
     assertThat(headers.value("x-bar")).containsExactly("abc")
   }
 
+  @Test
+  fun `removing specific header key performs a case-insentive header name lookup`() {
+    val headers = RequestHeadersBuilder(mutableMapOf())
+      .set("foo", mutableListOf("123"))
+      .remove("fOo")
+      .build()
+    assertThat(headers.caseSensitiveHeaders()).isEmpty()
+  }
+
   @Test
   fun `setting header replaces existing headers with matching name`() {
     val headers = RequestHeadersBuilder(mutableMapOf())
@@ -42,4 +59,39 @@ class HeadersBuilderTest {
       .build()
     assertThat(headers.value("x-foo")).containsExactly("abc")
   }
+
+  @Test
+  fun `setting header replaces performs a case-insensitive header name lookup`() {
+    val headers = RequestHeadersBuilder(mapOf())
+      .set("foo", mutableListOf("123"))
+      .set("fOo", mutableListOf("abc"))
+      .build()
+    assertThat(headers.caseSensitiveHeaders()).isEqualTo(mapOf("fOo" to listOf("abc")))
+  }
+
+  @Test
+  fun `test initialization is case-insensitive, preserves casing and processes headers in alphabetical order`() {
+    val headers = RequestHeadersBuilder(mutableMapOf("a" to mutableListOf("456"), "A" to mutableListOf("123"))).build()
+    assertThat(headers.caseSensitiveHeaders()).isEqualTo(mapOf("A" to listOf("123", "456")))
+  }
+
+  @Test
+  fun `test restricted headers are not settable`() {
+    val headers = RequestHeadersBuilder(method = RequestMethod.GET, authority = "example.com", path = "/")
+      .add("host", "example.com")
+      .add("Host", "example.com")
+      .add("hostWithSuffix", "foo.bar")
+      .set(":scheme", mutableListOf("http"))
+      .set(":path", mutableListOf("/nope"))
+      .build()
+      .caseSensitiveHeaders()
+    val expected = mapOf(
+      ":authority" to listOf("example.com"),
+      ":path" to listOf("/"),
+      ":method" to listOf("GET"),
+      ":scheme" to listOf("https"),
+      "hostWithSuffix" to listOf("foo.bar"),
+    )
+    assertThat(headers).isEqualTo(expected)
+  }
 }
diff --git a/mobile/test/kotlin/io/envoyproxy/envoymobile/HeadersContainerTest.kt b/mobile/test/kotlin/io/envoyproxy/envoymobile/HeadersContainerTest.kt
new file mode 100644
index 000000000000..483c4591810a
--- /dev/null
+++ b/mobile/test/kotlin/io/envoyproxy/envoymobile/HeadersContainerTest.kt
@@ -0,0 +1,81 @@
+package io.envoyproxy.envoymobile
+
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+
+class HeadersContainerest {
+  @Test
+  fun `instantiation preserves all headers from input headers map`() {
+    val headers = mapOf("a" to mutableListOf<String>("456"), "b" to mutableListOf<String>("123"))
+    val container = HeadersContainer(headers)
+    assertThat(container.caseSensitiveHeaders()).isEqualTo(headers)
+  }
+
+  @Test
+  fun `instantiation with mutable list of values is case-insensitive, preserves casing and processes in alphabetical order`() {
+    val container = HeadersContainer(mapOf("a" to mutableListOf<String>("456"), "A" to mutableListOf<String>("123")))
+    assertThat(container.caseSensitiveHeaders()).isEqualTo(mapOf("A" to listOf("123", "456")))
+  }
+
+  @Test
+  fun `creation with immutable list of values is case-insensitive, preserves casing and processes in alphabetical order`() {
+    val container = HeadersContainer.create(mapOf("a" to listOf<String>("456"), "A" to listOf<String>("123")))
+    assertThat(container.caseSensitiveHeaders()).isEqualTo(mapOf("A" to listOf("123", "456")))
+  }
+
+  @Test
+  fun `adding header adds to list of headers keys`() {
+    val container = HeadersContainer(mutableMapOf())
+    container.add("x-foo", "1")
+    container.add("x-foo", "2")
+    assertThat(container.value("x-foo")).containsExactly("1", "2")
+  }
+
+  @Test
+  fun `adding header performs a case-insensitive header lookup and preserves header name casing`() {
+    val container = HeadersContainer(mapOf())
+    container.add("x-FOO", "1")
+    container.add("x-foo", "2")
+
+    assertThat(container.value("x-foo")).isEqualTo(listOf("1", "2"))
+    assertThat(container.caseSensitiveHeaders()).isEqualTo(mapOf("x-FOO" to listOf("1", "2")))
+  }
+
+  @Test
+  fun `setting header adds to list of headers keys`() {
+    val container = HeadersContainer(mapOf())
+    container.set("x-foo", mutableListOf("abc"))
+
+    assertThat( container.value("x-foo")).isEqualTo(listOf("abc"))
+  }
+
+  @Test
+  fun `setting header overrides previous header values`() {
+    val container = HeadersContainer(mapOf())
+    container.add("x-FOO", "1")
+    container.add("x-foo", "2")
+    container.set("x-foo", mutableListOf("3"))
+
+    assertThat(container.value("x-foo")).isEqualTo(listOf("3"))
+  }
+
+  @Test
+  fun `removing header removes all of its values`() {
+    val container = HeadersContainer(mapOf())
+    container.add("x-foo", "1")
+    container.add("x-foo", "2")
+    container.remove("x-foo")
+
+    assertThat(container.value("x-foo")).isNull()
+  }
+
+  @Test
+  fun `removing header performs case-insensitive header name lookup`() {
+    val container = HeadersContainer(mapOf())
+    container.add("x-FOO", "1")
+    container.add("x-foo", "2")
+    container.remove("x-fOo")
+
+    assertThat(container.value("x-foo")).isNull()
+  }
+}
diff --git a/mobile/test/kotlin/io/envoyproxy/envoymobile/RequestHeadersBuilderTest.kt b/mobile/test/kotlin/io/envoyproxy/envoymobile/RequestHeadersBuilderTest.kt
index 88d0b0f5f158..035fd19fd1ac 100644
--- a/mobile/test/kotlin/io/envoyproxy/envoymobile/RequestHeadersBuilderTest.kt
+++ b/mobile/test/kotlin/io/envoyproxy/envoymobile/RequestHeadersBuilderTest.kt
@@ -103,9 +103,9 @@ class RequestHeadersBuilderTest {
       .add("hostWithSuffix", "foo.bar")
       .build()
 
-    assertThat(headers.allHeaders()).doesNotContainKey(":x-foo")
-    assertThat(headers.allHeaders()).doesNotContainKey("x-envoy-mobile-foo")
-    assertThat(headers.allHeaders()).doesNotContainKey("host")
+    assertThat(headers.caseSensitiveHeaders()).doesNotContainKey(":x-foo")
+    assertThat(headers.caseSensitiveHeaders()).doesNotContainKey("x-envoy-mobile-foo")
+    assertThat(headers.caseSensitiveHeaders()).doesNotContainKey("host")
     assertThat(headers.value("hostWithSuffix")).containsExactly("foo.bar")
   }
 
@@ -119,8 +119,8 @@ class RequestHeadersBuilderTest {
       .set("x-envoy-mobile-foo", mutableListOf("abc"))
       .build()
 
-    assertThat(headers.allHeaders()).doesNotContainKey(":x-foo")
-    assertThat(headers.allHeaders()).doesNotContainKey("x-envoy-mobile-foo")
+    assertThat(headers.caseSensitiveHeaders()).doesNotContainKey(":x-foo")
+    assertThat(headers.caseSensitiveHeaders()).doesNotContainKey("x-envoy-mobile-foo")
   }
 
   @Test
@@ -168,7 +168,7 @@ class RequestHeadersBuilderTest {
       .addRetryPolicy(retryPolicy)
       .build()
 
-    assertThat(headers.allHeaders()).containsAllEntriesOf(retryPolicyHeaders)
+    assertThat(headers.caseSensitiveHeaders()).containsAllEntriesOf(retryPolicyHeaders)
   }
 
   @Test
@@ -199,7 +199,7 @@ class RequestHeadersBuilderTest {
       .build()
     val headers2 = headers1.toRequestHeadersBuilder().build()
 
-    assertThat(headers1.allHeaders()).isEqualTo(headers2.allHeaders())
+    assertThat(headers1.caseSensitiveHeaders()).isEqualTo(headers2.caseSensitiveHeaders())
   }
 
   @Test
diff --git a/mobile/test/kotlin/io/envoyproxy/envoymobile/ResponseHeadersTest.kt b/mobile/test/kotlin/io/envoyproxy/envoymobile/ResponseHeadersTest.kt
index ec42c5583448..1aaf2e7bc7ff 100644
--- a/mobile/test/kotlin/io/envoyproxy/envoymobile/ResponseHeadersTest.kt
+++ b/mobile/test/kotlin/io/envoyproxy/envoymobile/ResponseHeadersTest.kt
@@ -43,4 +43,11 @@ class ResponseHeadersTest {
       .build()
     assertThat(headers.value(":status")).isNull()
   }
+
+  @Test
+  fun `header lookup is a case-insensitive operation`() {
+    val headers = ResponseHeaders(mapOf("FoO" to listOf("123")))
+    assertThat(headers.value("FoO")).isEqualTo(listOf("123"))
+    assertThat(headers.value("foo")).isEqualTo(listOf("123"))
+  }
 }
diff --git a/mobile/test/swift/HeadersBuilderTests.swift b/mobile/test/swift/HeadersBuilderTests.swift
index a92185ad25b7..6c7108f9774c 100644
--- a/mobile/test/swift/HeadersBuilderTests.swift
+++ b/mobile/test/swift/HeadersBuilderTests.swift
@@ -10,7 +10,7 @@ final class HeadersBuilderTests: XCTestCase {
     let headers = HeadersBuilder(headers: [:])
       .add(name: "x-foo", value: "1")
       .add(name: "x-foo", value: "2")
-      .allHeaders()
+      .caseSensitiveHeaders()
     XCTAssertEqual(["1", "2"], headers["x-foo"])
   }
 
@@ -19,7 +19,7 @@ final class HeadersBuilderTests: XCTestCase {
       .add(name: "x-foo", value: "1")
       .add(name: "x-foo", value: "2")
       .remove(name: "x-foo")
-      .allHeaders()
+      .caseSensitiveHeaders()
     XCTAssertNil(headers["x-foo"])
   }
 
@@ -28,7 +28,7 @@ final class HeadersBuilderTests: XCTestCase {
       .add(name: "x-foo", value: "123")
       .add(name: "x-bar", value: "abc")
       .remove(name: "x-foo")
-      .allHeaders()
+      .caseSensitiveHeaders()
     XCTAssertEqual(["x-bar": ["abc"]], headers)
   }
 
@@ -36,34 +36,34 @@ final class HeadersBuilderTests: XCTestCase {
     let headers = HeadersBuilder(headers: [:])
       .add(name: "x-foo", value: "123")
       .set(name: "x-foo", value: ["abc"])
-      .allHeaders()
+      .caseSensitiveHeaders()
     XCTAssertEqual(["x-foo": ["abc"]], headers)
   }
 
   func testInitializationIsCaseInsensitivePreservesCasingAndProcessesInAlphabeticalOrder() {
     let headers = HeadersBuilder(headers: ["a": ["456"], "A": ["123"]])
-    XCTAssertEqual(["A": ["123", "456"]], headers.allHeaders())
+    XCTAssertEqual(["A": ["123", "456"]], headers.caseSensitiveHeaders())
   }
 
   func testAddingHeaderIsCaseInsensitiveAndHeaderCasingIsPreserved() {
     let headers = HeadersBuilder(headers: [:])
     headers.add(name: "fOo", value: "abc")
     headers.add(name: "foo", value: "123")
-    XCTAssertEqual(["fOo": ["abc", "123"]], headers.allHeaders())
+    XCTAssertEqual(["fOo": ["abc", "123"]], headers.caseSensitiveHeaders())
   }
 
   func testSettingHeaderIsCaseInsensitiveAndHeaderCasingIsPreserved() {
     let headers = HeadersBuilder(headers: [:])
     headers.set(name: "foo", value: ["123"])
     headers.set(name: "fOo", value: ["abc"])
-    XCTAssertEqual(["fOo": ["abc"]], headers.allHeaders())
+    XCTAssertEqual(["fOo": ["abc"]], headers.caseSensitiveHeaders())
   }
 
   func testRemovingHeaderIsCaseInsensitive() {
     let headers = HeadersBuilder(headers: [:])
     headers.set(name: "foo", value: ["123"])
     headers.remove(name: "fOo")
-    XCTAssertEqual([:], headers.allHeaders())
+    XCTAssertEqual([:], headers.caseSensitiveHeaders())
   }
 
   func testRestrictedHeadersAreNotSettable() {
@@ -72,7 +72,7 @@ final class HeadersBuilderTests: XCTestCase {
       .add(name: "hostWithSuffix", value: "foo.bar")
       .set(name: ":scheme", value: ["http"])
       .set(name: ":path", value: ["/nope"])
-      .allHeaders()
+      .caseSensitiveHeaders()
     let expected = [
       ":authority": ["example.com"],
       ":path": ["/"],
diff --git a/mobile/test/swift/HeadersContainerTests.swift b/mobile/test/swift/HeadersContainerTests.swift
index d7ecd3b97691..d8ff2e4f0aa3 100644
--- a/mobile/test/swift/HeadersContainerTests.swift
+++ b/mobile/test/swift/HeadersContainerTests.swift
@@ -4,15 +4,15 @@ import XCTest
 final class HeadersContainerTests: XCTestCase {
   func testInitializationPreservesAllHeadersFromInputHeadersMap() {
     let container = HeadersContainer(headers: ["a": ["456"], "b": ["123"]])
-    XCTAssertEqual(["a": ["456"], "b": ["123"]], container.allHeaders())
+    XCTAssertEqual(["a": ["456"], "b": ["123"]], container.caseSensitiveHeaders())
   }
 
   func testInitializationIsCaseInsensitivePreservesCasingAndProcessesInAlphabeticalOrder() {
     let container = HeadersContainer(headers: ["a": ["456"], "A": ["123"]])
-    XCTAssertEqual(["A": ["123", "456"]], container.allHeaders())
+    XCTAssertEqual(["A": ["123", "456"]], container.caseSensitiveHeaders())
   }
 
-  func testAddingHeaderValueAddsToListOfHeaders() {
+  func testAddingHeaderAddsToListOfHeaders() {
     var container = HeadersContainer()
     container.add(name: "x-foo", value: "1")
     container.add(name: "x-foo", value: "2")
@@ -20,13 +20,13 @@ final class HeadersContainerTests: XCTestCase {
     XCTAssertEqual(["1", "2"], container.value(forName: "x-foo"))
   }
 
-  func testAddingHeaderValueIsCaseInsensitiveAndPreservesHeaderNameCasing() {
+  func testAddingHeaderIsCaseInsensitiveAndPreservesHeaderNameCasing() {
     var container = HeadersContainer()
     container.add(name: "x-FOO", value: "1")
     container.add(name: "x-foo", value: "2")
 
     XCTAssertEqual(["1", "2"], container.value(forName: "x-foo"))
-    XCTAssertEqual(["x-FOO": ["1", "2"]], container.allHeaders())
+    XCTAssertEqual(["x-FOO": ["1", "2"]], container.caseSensitiveHeaders())
   }
 
   func testSettingHeaderAddsToListOfHeaders() {
@@ -45,20 +45,20 @@ final class HeadersContainerTests: XCTestCase {
     XCTAssertEqual(["3"], container.value(forName: "x-foo"))
   }
 
-  func testSettingHeaderToNilRemovesAllOfItsValues() {
+  func testRemovingHeaderRemovesAllOfItsValues() {
     var container = HeadersContainer()
     container.add(name: "x-foo", value: "1")
     container.add(name: "x-foo", value: "2")
-    container.set(name: "x-foo", value: nil)
+    container.remove(name: "x-foo")
 
     XCTAssertNil(container.value(forName: "x-foo"))
   }
 
-  func testSettingHeaderToNilPerformsCaseInsensitiveHeaderNameLookup() {
+  func testRemovingHeaderPerformsCaseInsensitiveHeaderNameLookup() {
     var container = HeadersContainer()
     container.add(name: "x-FOO", value: "1")
     container.add(name: "x-foo", value: "2")
-    container.set(name: "x-foo", value: nil)
+    container.remove(name: "x-fOo")
 
     XCTAssertNil(container.value(forName: "x-foo"))
   }