diff --git a/akka-http-core/src/main/mima-filters/10.2.1.backwards.excludes/remove-Http2Shadow.excludes b/akka-http-core/src/main/mima-filters/10.2.1.backwards.excludes/remove-Http2Shadow.excludes
new file mode 100644
index 00000000000..af21af75fea
--- /dev/null
+++ b/akka-http-core/src/main/mima-filters/10.2.1.backwards.excludes/remove-Http2Shadow.excludes
@@ -0,0 +1,2 @@
+# Removal of internal class
+ProblemFilters.exclude[Problem]("akka.http.impl.engine.Http2Shadow*")
\ No newline at end of file
diff --git a/akka-http-core/src/main/scala/akka/http/impl/engine/Http2Shadow.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/Http2Shadow.scala
deleted file mode 100644
index d3a058cf928..00000000000
--- a/akka-http-core/src/main/scala/akka/http/impl/engine/Http2Shadow.scala
+++ /dev/null
@@ -1,67 +0,0 @@
-/*
- * Copyright (C) 2009-2020 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package akka.http.impl.engine
-
-import akka.actor.{ ActorSystem, ExtendedActorSystem }
-import akka.annotation.InternalApi
-import akka.event.LoggingAdapter
-import akka.http.scaladsl.Http.ServerBinding
-import akka.http.scaladsl.ConnectionContext
-import akka.http.scaladsl.model.{ HttpRequest, HttpResponse }
-import akka.http.scaladsl.settings.ServerSettings
-import akka.stream.{ ActorMaterializerHelper, Materializer }
-
-import scala.concurrent.Future
-
-/** INTERNAL API: Uses reflection to reach for Http2 support if available or fails with an exception */
-@InternalApi
-private[akka] object Http2Shadow {
-
-  type ShadowHttp2 = AnyRef
-  type ShadowHttp2Ext = {
-    def bindAndHandleAsync(
-      handler:   HttpRequest => Future[HttpResponse],
-      interface: String, port: Int,
-      httpContext: ConnectionContext,
-      settings:    ServerSettings,
-      parallelism: Int,
-      log:         LoggingAdapter)(implicit fm: Materializer): Future[ServerBinding]
-  }
-
-  def bindAndHandleAsync(
-    handler:   HttpRequest => Future[HttpResponse],
-    interface: String, port: Int,
-    httpContext: ConnectionContext,
-    settings:    ServerSettings,
-    parallelism: Int,
-    log:         LoggingAdapter)(implicit fm: Materializer): Future[ServerBinding] = {
-
-    val mat = ActorMaterializerHelper.downcast(fm)
-
-    try {
-      val system = mat.system.asInstanceOf[ExtendedActorSystem]
-      val extensionIdClazz = system.dynamicAccess.getClassFor[ShadowHttp2]("akka.http.scaladsl.Http2").get
-
-      val extensionInstance: ShadowHttp2Ext = extensionIdClazz.getMethod("get", Array(classOf[ActorSystem]): _*)
-        .invoke(null, system).asInstanceOf[ShadowHttp2Ext]
-
-      import scala.language.reflectiveCalls
-      extensionInstance.bindAndHandleAsync(
-        handler,
-        interface, port,
-        httpContext,
-        settings,
-        parallelism,
-        log)(fm)
-    } catch {
-      case ex: Throwable => throw Http2SupportNotPresentException(ex)
-    }
-  }
-
-  final case class Http2SupportNotPresentException(cause: Throwable)
-    extends RuntimeException("Unable to invoke HTTP2 binding logic (as enabled setting `akka.http.server.enable-http2`). " +
-      """Please make sure that `"com.typesafe.akka" %% "akka-http2-support" % AkkaHttpVersion` is on the classpath.""", cause)
-
-}
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/BufferedOutletSupport.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/BufferedOutletSupport.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/BufferedOutletSupport.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/BufferedOutletSupport.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/ByteFlag.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/ByteFlag.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/ByteFlag.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/ByteFlag.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/FrameEvent.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/FrameEvent.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/FrameEvent.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/FrameEvent.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/FrameLogger.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/FrameLogger.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/FrameLogger.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/FrameLogger.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/scaladsl/Http2.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2.scala
similarity index 95%
rename from akka-http2-support/src/main/scala/akka/http/scaladsl/Http2.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2.scala
index 92fe6cfe26f..55d0d475e96 100644
--- a/akka-http2-support/src/main/scala/akka/http/scaladsl/Http2.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2.scala
@@ -2,14 +2,15 @@
  * Copyright (C) 2009-2020 Lightbend Inc. <https://www.lightbend.com>
  */
 
-package akka.http.scaladsl
+package akka.http.impl.engine.http2
 
 import akka.actor.{ ActorSystem, ClassicActorSystemProvider, ExtendedActorSystem, Extension, ExtensionId, ExtensionIdProvider }
+import akka.annotation.InternalApi
 import akka.dispatch.ExecutionContexts
 import akka.event.LoggingAdapter
-import akka.http.impl.engine.http2.{ Http2AlpnSupport, Http2Blueprint, ProtocolSwitch }
 import akka.http.impl.engine.server.{ MasterServerTerminator, UpgradeToOtherProtocolResponseHeader }
 import akka.http.impl.util.LogByteStringTools
+import akka.http.scaladsl.{ ConnectionContext, Http, HttpsConnectionContext }
 import akka.http.scaladsl.Http.ServerBinding
 import akka.http.scaladsl.model._
 import akka.http.scaladsl.model.headers.{ Connection, RawHeader, Upgrade, UpgradeProtocol }
@@ -30,8 +31,13 @@ import scala.concurrent.duration.Duration
 import scala.util.control.NonFatal
 import scala.util.{ Failure, Success }
 
-/** Entry point for Http/2 server */
-final class Http2Ext(private val config: Config)(implicit val system: ActorSystem)
+/**
+ * INTERNAL API
+ *
+ * Internal entry points for Http/2 server
+ */
+@InternalApi
+private[http] final class Http2Ext(private val config: Config)(implicit val system: ActorSystem)
   extends akka.actor.Extension {
   // FIXME: won't having the same package as top-level break osgi?
 
@@ -210,7 +216,9 @@ final class Http2Ext(private val config: Config)(implicit val system: ActorSyste
   }
 }
 
-object Http2 extends ExtensionId[Http2Ext] with ExtensionIdProvider {
+/** INTERNAL API */
+@InternalApi
+private[http] object Http2 extends ExtensionId[Http2Ext] with ExtensionIdProvider {
   val streamId = AttributeKey[Int]("x-http2-stream-id")
 
   override def get(system: ActorSystem): Http2Ext = super.get(system)
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2AlpnSupport.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2AlpnSupport.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2AlpnSupport.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2AlpnSupport.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Blueprint.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Blueprint.scala
similarity index 99%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Blueprint.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Blueprint.scala
index c0913160ca7..a93a7ecde52 100644
--- a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Blueprint.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Blueprint.scala
@@ -15,7 +15,6 @@ import akka.http.impl.engine.http2.hpack.{ HeaderCompression, HeaderDecompressio
 import akka.http.impl.engine.parsing.HttpHeaderParser
 import akka.http.impl.util.LogByteStringTools.logTLSBidiBySetting
 import akka.http.impl.util.StreamUtils
-import akka.http.scaladsl.Http2
 import akka.http.scaladsl.model._
 import akka.http.scaladsl.settings.{ ClientConnectionSettings, Http2CommonSettings, ParserSettings, ServerSettings }
 import akka.stream.TLSProtocol._
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Compliance.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Compliance.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Compliance.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Compliance.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Multiplexer.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Multiplexer.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Multiplexer.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Multiplexer.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Protocol.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Protocol.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2Protocol.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2Protocol.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2ServerDemux.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2ServerDemux.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2ServerDemux.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2ServerDemux.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/scaladsl/model/http2/Http2SettingsHeader.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2SettingsHeader.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/scaladsl/model/http2/Http2SettingsHeader.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2SettingsHeader.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2StreamHandling.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2StreamHandling.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/Http2StreamHandling.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/Http2StreamHandling.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/IncomingFlowController.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/IncomingFlowController.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/IncomingFlowController.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/IncomingFlowController.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/PriorityTree.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/PriorityTree.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/PriorityTree.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/PriorityTree.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/ProtocolSwitch.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/ProtocolSwitch.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/ProtocolSwitch.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/ProtocolSwitch.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/RequestParsing.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/RequestParsing.scala
similarity index 99%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/RequestParsing.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/RequestParsing.scala
index a45b71a5ca1..37d93d06269 100644
--- a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/RequestParsing.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/RequestParsing.scala
@@ -9,7 +9,7 @@ import javax.net.ssl.SSLSession
 import akka.annotation.InternalApi
 import akka.http.impl.engine.parsing.HttpHeaderParser
 import akka.http.impl.engine.server.HttpAttributes
-import akka.http.scaladsl.{ Http2, model }
+import akka.http.scaladsl.model
 import akka.http.scaladsl.model._
 import akka.http.scaladsl.model.headers.{ `Remote-Address`, `Tls-Session-Info` }
 import akka.http.scaladsl.settings.ServerSettings
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/ResponseRendering.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/ResponseRendering.scala
similarity index 99%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/ResponseRendering.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/ResponseRendering.scala
index 6bab75ddcf3..3a265a46daf 100644
--- a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/ResponseRendering.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/ResponseRendering.scala
@@ -13,7 +13,6 @@ import akka.http.scaladsl.settings.ServerSettings
 import scala.collection.immutable
 import scala.collection.immutable.VectorBuilder
 import FrameEvent.ParsedHeadersFrame
-import akka.http.scaladsl.Http2
 
 private[http2] object ResponseRendering {
 
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/StreamPrioritizer.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/StreamPrioritizer.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/StreamPrioritizer.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/StreamPrioritizer.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/client/RequestRendering.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/client/RequestRendering.scala
similarity index 91%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/client/RequestRendering.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/client/RequestRendering.scala
index e2dc345a406..7c42e8a01d4 100644
--- a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/client/RequestRendering.scala
+++ b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/client/RequestRendering.scala
@@ -10,8 +10,7 @@ import java.util.concurrent.atomic.AtomicInteger
 import akka.annotation.InternalApi
 import akka.event.LoggingAdapter
 import akka.http.impl.engine.http2.FrameEvent.ParsedHeadersFrame
-import akka.http.scaladsl.model.http2.RequestResponseAssociation
-import akka.http.scaladsl.model.{ ContentTypes, HttpEntity, HttpRequest }
+import akka.http.scaladsl.model.{ HttpRequest, RequestResponseAssociation }
 
 import scala.collection.immutable.VectorBuilder
 
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/client/ResponseParsing.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/client/ResponseParsing.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/client/ResponseParsing.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/client/ResponseParsing.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/framing/FrameRenderer.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/framing/FrameRenderer.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/framing/FrameRenderer.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/framing/FrameRenderer.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/framing/Http2FrameParsing.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/framing/Http2FrameParsing.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/framing/Http2FrameParsing.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/framing/Http2FrameParsing.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/framing/Http2FrameRendering.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/framing/Http2FrameRendering.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/framing/Http2FrameRendering.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/framing/Http2FrameRendering.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/hpack/ByteStringInputStream.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/hpack/ByteStringInputStream.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/hpack/ByteStringInputStream.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/hpack/ByteStringInputStream.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/hpack/HandleOrPassOnStage.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/hpack/HandleOrPassOnStage.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/hpack/HandleOrPassOnStage.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/hpack/HandleOrPassOnStage.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/hpack/HeaderCompression.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/hpack/HeaderCompression.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/hpack/HeaderCompression.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/hpack/HeaderCompression.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/hpack/HeaderDecompression.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/hpack/HeaderDecompression.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/hpack/HeaderDecompression.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/hpack/HeaderDecompression.scala
diff --git a/akka-http2-support/src/main/scala/akka/http/impl/engine/http2/util/AsciiTreeLayout.scala b/akka-http-core/src/main/scala/akka/http/impl/engine/http2/util/AsciiTreeLayout.scala
similarity index 100%
rename from akka-http2-support/src/main/scala/akka/http/impl/engine/http2/util/AsciiTreeLayout.scala
rename to akka-http-core/src/main/scala/akka/http/impl/engine/http2/util/AsciiTreeLayout.scala
diff --git a/akka-http-core/src/main/scala/akka/http/scaladsl/Http.scala b/akka-http-core/src/main/scala/akka/http/scaladsl/Http.scala
index ade61ad1fea..37ef500138c 100644
--- a/akka-http-core/src/main/scala/akka/http/scaladsl/Http.scala
+++ b/akka-http-core/src/main/scala/akka/http/scaladsl/Http.scala
@@ -13,9 +13,9 @@ import akka.annotation.DoNotInherit
 import akka.annotation.InternalApi
 import akka.dispatch.ExecutionContexts
 import akka.event.{ Logging, LoggingAdapter }
-import akka.http.impl.engine.Http2Shadow
 import akka.http.impl.engine.HttpConnectionIdleTimeoutBidi
 import akka.http.impl.engine.client._
+import akka.http.impl.engine.http2.Http2
 import akka.http.impl.engine.server._
 import akka.http.impl.engine.ws.WebSocketClientBlueprint
 import akka.http.impl.settings.{ ConnectionPoolSetup, HostConnectionPoolSetup }
@@ -341,7 +341,7 @@ class HttpExt private[http] (private val config: Config)(implicit val system: Ex
         if (parallelism > 0) settings.mapHttp2Settings(_.withMaxConcurrentStreams(parallelism))
         else if (parallelism < 0) throw new IllegalArgumentException("Only positive values allowed for `parallelism`.")
         else settings
-      Http2Shadow.bindAndHandleAsync(handler, interface, port, connectionContext, definitiveSettings, definitiveSettings.http2Settings.maxConcurrentStreams, log)(fm)
+      Http2().bindAndHandleAsync(handler, interface, port, connectionContext, definitiveSettings, definitiveSettings.http2Settings.maxConcurrentStreams, log)(fm)
     } else {
       val definitiveParallelism =
         if (parallelism > 0) parallelism
diff --git a/akka-http2-support/src/main/scala/akka/http/scaladsl/model/http2/RequestResponseAssociation.scala b/akka-http-core/src/main/scala/akka/http/scaladsl/model/RequestResponseAssociation.scala
similarity index 64%
rename from akka-http2-support/src/main/scala/akka/http/scaladsl/model/http2/RequestResponseAssociation.scala
rename to akka-http-core/src/main/scala/akka/http/scaladsl/model/RequestResponseAssociation.scala
index 5424434c945..4f62ea99338 100644
--- a/akka-http2-support/src/main/scala/akka/http/scaladsl/model/http2/RequestResponseAssociation.scala
+++ b/akka-http-core/src/main/scala/akka/http/scaladsl/model/RequestResponseAssociation.scala
@@ -2,10 +2,18 @@
  * Copyright (C) 2020 Lightbend Inc. <https://www.lightbend.com>
  */
 
-package akka.http.scaladsl.model.http2
+package akka.http.scaladsl.model
+
+import akka.annotation.ApiMayChange
 
 /**
  * A marker trait for attribute values that should be (automatically) carried over from request to response.
  */
+@ApiMayChange
 trait RequestResponseAssociation
+
+/**
+ * A simple value holder class implementing RequestResponseAssociation.
+ */
+@ApiMayChange
 final case class SimpleRequestResponseAttribute[T](value: T) extends RequestResponseAssociation
diff --git a/akka-http2-support/src/main/scala/akka/http/scaladsl/model/http2/Http2Exception.scala b/akka-http-core/src/main/scala/akka/http/scaladsl/model/http2/Http2Exception.scala
similarity index 92%
rename from akka-http2-support/src/main/scala/akka/http/scaladsl/model/http2/Http2Exception.scala
rename to akka-http-core/src/main/scala/akka/http/scaladsl/model/http2/Http2Exception.scala
index 83edee5b6f0..2002eb602af 100644
--- a/akka-http2-support/src/main/scala/akka/http/scaladsl/model/http2/Http2Exception.scala
+++ b/akka-http-core/src/main/scala/akka/http/scaladsl/model/http2/Http2Exception.scala
@@ -4,6 +4,7 @@
 
 package akka.http.scaladsl.model.http2
 
+import akka.annotation.ApiMayChange
 import akka.http.impl.engine.http2.Http2Protocol.ErrorCode
 
 import scala.util.control.NoStackTrace
@@ -11,11 +12,13 @@ import scala.util.control.NoStackTrace
 /**
  * Base class for HTTP2 exceptions.
  */
+@ApiMayChange
 class Http2Exception(msg: String) extends RuntimeException(msg)
 
 /**
  * Exception that will be reported on the request entity stream when the peer closed the stream.
  */
+@ApiMayChange
 class PeerClosedStreamException(val streamId: Int, val errorCode: String, val numericErrorCode: Int)
   extends Http2Exception(f"Stream with ID [$streamId%d] was closed by peer with code $errorCode%s(0x$numericErrorCode%02x)") with NoStackTrace {
   private[http] def this(streamId: Int, errorCode: ErrorCode) = this(streamId, errorCode.toString, errorCode.id)
diff --git a/akka-http2-support/src/test/java/akka/http/javadsl/Http2JavaServerTest.java b/akka-http2-support/src/test/java/akka/http/javadsl/Http2JavaServerTest.java
index b7ee5320430..95987864122 100644
--- a/akka-http2-support/src/test/java/akka/http/javadsl/Http2JavaServerTest.java
+++ b/akka-http2-support/src/test/java/akka/http/javadsl/Http2JavaServerTest.java
@@ -8,10 +8,7 @@
 import akka.http.impl.util.ExampleHttpContexts;
 import akka.http.javadsl.model.HttpRequest;
 import akka.http.javadsl.model.HttpResponse;
-import akka.http.javadsl.HttpsConnectionContext;
 import akka.japi.function.Function;
-import akka.stream.ActorMaterializer;
-import akka.stream.Materializer;
 import com.typesafe.config.Config;
 import com.typesafe.config.ConfigFactory;
 
@@ -31,7 +28,6 @@ public static void main(String[] args) {
       "akka.http.server.preview.enable-http2 = on\n"
     );
     ActorSystem system = ActorSystem.create("ServerTest", testConf);
-    Materializer materializer = ActorMaterializer.create(system);
 
     Function<HttpRequest, CompletionStage<HttpResponse>> handler =
       request -> CompletableFuture.completedFuture(HttpResponse.create().withEntity(request.entity()));
diff --git a/akka-http2-support/src/test/scala/akka/http/h2spec/H2SpecIntegrationSpec.scala b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/H2SpecIntegrationSpec.scala
similarity index 95%
rename from akka-http2-support/src/test/scala/akka/http/h2spec/H2SpecIntegrationSpec.scala
rename to akka-http2-support/src/test/scala/akka/http/impl/engine/http2/H2SpecIntegrationSpec.scala
index 1468eb6e6b6..96d45d09d12 100644
--- a/akka-http2-support/src/test/scala/akka/http/h2spec/H2SpecIntegrationSpec.scala
+++ b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/H2SpecIntegrationSpec.scala
@@ -2,14 +2,14 @@
  * Copyright (C) 2009-2020 Lightbend Inc. <https://www.lightbend.com>
  */
 
-package akka.http.h2spec
+package akka.http.impl.engine.http2
 
 import java.io.File
 import java.util.concurrent.atomic.AtomicBoolean
 
 import akka.http.impl.util.{ ExampleHttpContexts, WithLogCapturing }
+import akka.http.scaladsl.Http
 import akka.http.scaladsl.server.Directives
-import akka.http.scaladsl.Http2
 import akka.stream.ActorMaterializer
 import akka.testkit._
 import akka.util.ByteString
@@ -25,6 +25,7 @@ class H2SpecIntegrationSpec extends AkkaSpec(
        loglevel = DEBUG
        loggers = ["akka.http.impl.util.SilenceAllTestEventListener"]
        http.server.log-unencrypted-network-bytes = off
+       http.server.preview.enable-http2 = on
        http.server.http2.log-frames = on
 
        actor.serialize-creators = off
@@ -43,7 +44,12 @@ class H2SpecIntegrationSpec extends AkkaSpec(
     complete(data)
   }
 
-  val binding = Http2().bindAndHandleAsync(echo, "127.0.0.1", 0, ExampleHttpContexts.exampleServerContext).futureValue
+  val binding =
+    Http()
+      .newServerAt("127.0.0.1", 0)
+      .enableHttps(ExampleHttpContexts.exampleServerContext)
+      .bind(echo)
+      .futureValue
   val port = binding.localAddress.getPort
 
   "H2Spec" must {
diff --git a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/H2cUpgradeSpec.scala b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/H2cUpgradeSpec.scala
index d7c254d46df..6654bf0eb80 100644
--- a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/H2cUpgradeSpec.scala
+++ b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/H2cUpgradeSpec.scala
@@ -6,7 +6,7 @@ package akka.http.impl.engine.http2
 
 import akka.http.impl.util._
 import akka.http.scaladsl.model.{ HttpResponse, StatusCodes }
-import akka.http.scaladsl.{ Http2, HttpConnectionContext }
+import akka.http.scaladsl.HttpConnectionContext
 import akka.stream.scaladsl.{ Source, Tcp }
 import akka.util.ByteString
 
diff --git a/akka-http2-support/src/test/scala/akka/http/scaladsl/Http2ClientApp.scala b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientApp.scala
similarity index 92%
rename from akka-http2-support/src/test/scala/akka/http/scaladsl/Http2ClientApp.scala
rename to akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientApp.scala
index 7e992fa0910..183a6fd60c3 100644
--- a/akka-http2-support/src/test/scala/akka/http/scaladsl/Http2ClientApp.scala
+++ b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientApp.scala
@@ -2,21 +2,20 @@
  * Copyright (C) 2020 Lightbend Inc. <https://www.lightbend.com>
  */
 
-package akka.http.scaladsl
+package akka.http.impl.engine.http2
 
 import akka.actor.ActorSystem
-import akka.http.scaladsl.model.headers
 import akka.http.scaladsl.model.headers.HttpEncodings
-import akka.http.scaladsl.model.http2.RequestResponseAssociation
-import akka.http.scaladsl.model.{ AttributeKey, HttpRequest, HttpResponse }
+import akka.http.scaladsl.model.{ AttributeKey, HttpRequest, HttpResponse, RequestResponseAssociation, headers }
 import akka.stream.OverflowStrategy
 import akka.stream.scaladsl.{ Flow, Sink, Source }
 import com.typesafe.config.ConfigFactory
 
-import scala.concurrent.{ Future, Promise }
 import scala.concurrent.duration._
+import scala.concurrent.{ Future, Promise }
 
 /** A small example app that shows how to use the HTTP/2 client API currently against actual internet servers */
+// needs to live in impl.engine.http2 for now as we have no public access to the internal HTTP2 client
 object Http2ClientApp extends App {
   val config =
     ConfigFactory.parseString(
@@ -30,7 +29,7 @@ object Http2ClientApp extends App {
   implicit val system = ActorSystem("Http2ClientApp", config)
   implicit val ec = system.dispatcher
 
-  val dispatch = singleRequest(Http2().outgoingConnection("doc.akka.io"))
+  val dispatch = singleRequest(Http2().outgoingConnection("doc.akka.io")) // FIXME: replace with public API
 
   dispatch(HttpRequest(uri = "https://doc.akka.io/api/akka/current/akka/actor/typed/scaladsl/index.html", headers = headers.`Accept-Encoding`(HttpEncodings.gzip) :: Nil)).onComplete { res =>
     println(s"[1] Got index.html: $res")
diff --git a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientServerSpec.scala b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientServerSpec.scala
index 21a6d193c73..16e7f3609b0 100644
--- a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientServerSpec.scala
+++ b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientServerSpec.scala
@@ -6,13 +6,11 @@ package akka.http.impl.engine.http2
 
 import akka.http.impl.engine.ws.ByteStringSinkProbe
 import akka.http.impl.util.{ AkkaSpecWithMaterializer, ExampleHttpContexts }
-import akka.http.scaladsl.model.headers
+import akka.http.scaladsl.model.{ AttributeKey, ContentTypes, HttpEntity, HttpHeader, HttpMethod, HttpMethods, HttpRequest, HttpResponse, RequestResponseAssociation, StatusCode, StatusCodes, Uri, headers }
 import akka.http.scaladsl.model.headers.HttpEncodings
-import akka.http.scaladsl.model.http2.RequestResponseAssociation
-import akka.http.scaladsl.model.{ AttributeKey, ContentTypes, HttpEntity, HttpHeader, HttpMethod, HttpMethods, HttpRequest, HttpResponse, StatusCode, StatusCodes, Uri }
 import akka.http.scaladsl.settings.ClientConnectionSettings
 import akka.http.scaladsl.unmarshalling.Unmarshal
-import akka.http.scaladsl.{ Http, Http2 }
+import akka.http.scaladsl.Http
 import akka.stream.scaladsl.{ Sink, Source }
 import akka.stream.testkit.{ TestPublisher, TestSubscriber }
 import akka.testkit.TestProbe
diff --git a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientSpec.scala b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientSpec.scala
index 1aa5ffe425e..0ecd9112a43 100644
--- a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientSpec.scala
+++ b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ClientSpec.scala
@@ -9,7 +9,6 @@ import akka.event.Logging
 import akka.http.impl.engine.http2.FrameEvent._
 import akka.http.impl.engine.http2.Http2Protocol.ErrorCode
 import akka.http.impl.util.{ AkkaSpecWithMaterializer, LogByteStringTools }
-import akka.http.scaladsl.Http2
 import akka.http.scaladsl.model.HttpEntity.Strict
 import akka.http.scaladsl.model._
 import akka.http.scaladsl.settings.ClientConnectionSettings
@@ -58,10 +57,9 @@ class Http2ClientSpec extends AkkaSpecWithMaterializer("""
       "GET request in one HEADERS frame" in new SimpleRequestResponseRoundtripSetup {
         requestResponseRoundtrip(
           streamId = 1,
-          request = HttpRequest(uri = "http://www.example.com/"),
+          request = HttpRequest(uri = "https://www.example.com/"),
           expectedHeaders = Seq(
             ":method" -> "GET",
-            // TODO check if this makes sense?
             ":scheme" -> "https",
             ":authority" -> "www.example.com",
             ":path" -> "/",
@@ -93,7 +91,7 @@ class Http2ClientSpec extends AkkaSpecWithMaterializer("""
       "GOAWAY when the response to a second request on different stream has an invalid headers frame" in new SimpleRequestResponseRoundtripSetup {
         requestResponseRoundtrip(
           streamId = 1,
-          request = HttpRequest(uri = "http://www.example.com/"),
+          request = HttpRequest(uri = "https://www.example.com/"),
           expectedHeaders = Seq(
             ":method" -> "GET",
             // TODO check if this makes sense?
@@ -111,7 +109,7 @@ class Http2ClientSpec extends AkkaSpecWithMaterializer("""
               .withEntity(Strict(ContentTypes.NoContentType, ByteString.empty))
         )
 
-        emitRequest(3, HttpRequest(uri = "http://www.example.com/"))
+        emitRequest(3, HttpRequest(uri = "https://www.example.com/"))
         expectFrame() shouldBe a[HeadersFrame]
 
         val incorrectHeaderBlock = hex"00 00 01 01 05 00 00 00 01 40"
diff --git a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2FrameSending.scala b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2FrameSending.scala
index 752b7cc2f88..c4fdd05b4da 100644
--- a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2FrameSending.scala
+++ b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2FrameSending.scala
@@ -11,8 +11,8 @@ import akka.http.impl.engine.http2.Http2Protocol.{ ErrorCode, Flags, FrameType,
 import akka.http.impl.engine.http2.framing.FrameRenderer
 import akka.util.{ ByteString, ByteStringBuilder }
 
-trait Http2FrameSending {
-  def sendBytes(bytes: ByteString)
+private[http2] trait Http2FrameSending {
+  def sendBytes(bytes: ByteString): Unit
 
   def sendFrame(frame: FrameEvent): Unit =
     sendBytes(FrameRenderer.render(frame))
diff --git a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ServerSpec.scala b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ServerSpec.scala
index a05c9b7a4d7..1b50c5f2db9 100644
--- a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ServerSpec.scala
+++ b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/Http2ServerSpec.scala
@@ -30,7 +30,6 @@ import scala.concurrent.{ Await, Future, Promise }
 import scala.concurrent.duration._
 import FrameEvent._
 import akka.event.Logging
-import akka.http.scaladsl.Http2
 import akka.stream.Attributes
 import akka.stream.Attributes.LogLevels
 import akka.stream.testkit.scaladsl.StreamTestKit
diff --git a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/RequestParsingSpec.scala b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/RequestParsingSpec.scala
index a07e4c077a4..dee55d30d65 100644
--- a/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/RequestParsingSpec.scala
+++ b/akka-http2-support/src/test/scala/akka/http/impl/engine/http2/RequestParsingSpec.scala
@@ -14,7 +14,6 @@ import akka.testkit.AkkaSpec
 import akka.util.ByteString
 import org.scalatest.{ Inside, Inspectors }
 import FrameEvent._
-import akka.http.scaladsl.Http2
 
 class RequestParsingSpec extends AkkaSpec() with Inside with Inspectors {
 
diff --git a/akka-http2-support/src/test/scala/akka/http/scaladsl/Http2BindingViaConfigSpec.scala b/akka-http2-support/src/test/scala/akka/http/scaladsl/Http2BindingViaConfigSpec.scala
deleted file mode 100644
index 14663bf4391..00000000000
--- a/akka-http2-support/src/test/scala/akka/http/scaladsl/Http2BindingViaConfigSpec.scala
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * Copyright (C) 2009-2020 Lightbend Inc. <https://www.lightbend.com>
- */
-
-package akka.http.scaladsl
-
-import akka.event.Logging
-import akka.http.impl.util.ExampleHttpContexts
-import akka.http.scaladsl.model._
-import akka.stream._
-import akka.testkit.{ AkkaSpec, TestProbe }
-
-import scala.concurrent.Future
-import scala.concurrent.duration.{ Duration, _ }
-
-class Http2BindingViaConfigSpec extends AkkaSpec("""
-    akka.http.server.preview.enable-http2 = on
-
-    akka.loglevel = DEBUG
-    akka.log-dead-letters = off
-  """) {
-  implicit val mat = ActorMaterializer()
-  import system.dispatcher
-
-  var binding: Future[Http.ServerBinding] = _ // initialized atStartup
-
-  val helloWorldHandler: HttpRequest => Future[HttpResponse] =
-    _ => Future(HttpResponse(entity = "Hello!"))
-
-  "akka.http.server.enable-http2" should {
-    "bind using HTTP/2 with HttpsConnectionContext provided" in {
-      // since we're in akka-http core here, the http2 support is not available on classpath,
-      // so the setting + binding should fail
-
-      var binding: Future[Http.ServerBinding] = null
-      try {
-        val p = TestProbe()
-        system.eventStream.subscribe(p.ref, classOf[Logging.Debug])
-
-        val connectionContext = ExampleHttpContexts.exampleServerContext
-        binding =
-          Http().newServerAt("localhost", 0)
-            .enableHttps(connectionContext)
-            .bind(helloWorldHandler)
-
-        // TODO we currently don't verify it really bound as h2, since we don't have a client lib
-        fishForDebugMessage(p, "Binding server using HTTP/2")
-      } finally if (binding ne null) binding.map(_.unbind())
-    }
-  }
-
-  "Http2Shadow" should {
-    "have ShadowHttp2Ext type aligned with real Http2Ext" in {
-      val ext: Http2Ext = Http2()
-      // the Shadow is a structural type, so this assignment only works
-      // if all the methods it requires exist on the real class
-      val typed: akka.http.impl.engine.Http2Shadow.ShadowHttp2Ext = ext
-      val _ = typed.bindAndHandleAsync _ // to avoid not-used warnings
-    }
-  }
-
-  private def fishForDebugMessage(a: TestProbe, messagePrefix: String, max: Duration = 3.seconds): Unit = {
-    a.fishForMessage(max, hint = "expected debug message part: " + messagePrefix) {
-      case Logging.Debug(_, _, msg: String) if msg contains messagePrefix => true
-      case _ => false
-    }
-  }
-
-}
diff --git a/docs/src/main/paradox/compatibility-guidelines.md b/docs/src/main/paradox/compatibility-guidelines.md
index f79b12f9545..ca8360ef5f9 100644
--- a/docs/src/main/paradox/compatibility-guidelines.md
+++ b/docs/src/main/paradox/compatibility-guidelines.md
@@ -81,6 +81,10 @@ Scala
     akka.http.scaladsl.model.headers.CacheDirectives.immutableDirective
     akka.http.scaladsl.model.headers.X-Forwarded-Host
     akka.http.scaladsl.model.headers.X-Forwarded-Proto
+    akka.http.scaladsl.model.http2.PeerClosedStreamException
+    akka.http.scaladsl.model.http2.Http2Exception
+    akka.http.scaladsl.model.SimpleRequestResponseAttribute
+    akka.http.scaladsl.model.RequestResponseAssociation
     ```
 
 Java
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 3e0726d10bc..0e0f5a6af51 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -91,6 +91,7 @@ object Dependencies {
   )
 
   lazy val httpCore = l ++= Seq(
+    hpack,
     Test.sprayJson, // for WS Autobahn test metadata
     Test.scalatest, Test.scalatestplusScalacheck, Test.scalatestplusJUnit, Test.junit
   )
@@ -103,7 +104,7 @@ object Dependencies {
 
   lazy val http = Seq()
 
-  lazy val http2 = l ++= Seq(hpack)
+  lazy val http2 = l ++= Seq()
 
   lazy val http2Support = l ++= Seq(Test.h2spec)