diff --git a/akka-stream-tests-tck/src/test/scala-jdk9-only/akka/stream/tck/IterablePublisherViaJavaFlowPublisherTest.scala b/akka-stream-tests-tck/src/test/scala-jdk9-only/akka/stream/tck/IterablePublisherViaJavaFlowPublisherTest.scala
index 2aa9aa4809e..8630d79214e 100644
--- a/akka-stream-tests-tck/src/test/scala-jdk9-only/akka/stream/tck/IterablePublisherViaJavaFlowPublisherTest.scala
+++ b/akka-stream-tests-tck/src/test/scala-jdk9-only/akka/stream/tck/IterablePublisherViaJavaFlowPublisherTest.scala
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017-2018 Lightbend Inc. <https://www.lightbend.com>
+ * Copyright (C) 2017-2019 Lightbend Inc. <https://www.lightbend.com>
  */
 
 package akka.stream.tck
diff --git a/akka-stream-tests/src/test/java-jdk9-only/akka/stream/javadsl/JavaFlowSupportCompileTest.java b/akka-stream-tests/src/test/java-jdk9-only/akka/stream/javadsl/JavaFlowSupportCompileTest.java
index eaaf743fd13..3e1d70203f1 100644
--- a/akka-stream-tests/src/test/java-jdk9-only/akka/stream/javadsl/JavaFlowSupportCompileTest.java
+++ b/akka-stream-tests/src/test/java-jdk9-only/akka/stream/javadsl/JavaFlowSupportCompileTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017-2018 Lightbend Inc. <https://www.lightbend.com>
+ * Copyright (C) 2017-2019 Lightbend Inc. <https://www.lightbend.com>
  */
 
 package akka.stream.javadsl;
diff --git a/akka-stream-tests/src/test/scala-jdk9-only/akka/stream/scaladsl/FlowPublisherSinkSpec.scala b/akka-stream-tests/src/test/scala-jdk9-only/akka/stream/scaladsl/FlowPublisherSinkSpec.scala
index aed92b472fa..3654de7aafa 100644
--- a/akka-stream-tests/src/test/scala-jdk9-only/akka/stream/scaladsl/FlowPublisherSinkSpec.scala
+++ b/akka-stream-tests/src/test/scala-jdk9-only/akka/stream/scaladsl/FlowPublisherSinkSpec.scala
@@ -1,5 +1,5 @@
-/**
- * Copyright (C) 2014-2018 Lightbend Inc. <https://www.lightbend.com>
+/*
+ * Copyright (C) 2014-2019 Lightbend Inc. <https://www.lightbend.com>
  */
 
 package akka.stream.scaladsl
diff --git a/akka-stream/src/main/java-jdk-9/akka/stream/javadsl/JavaFlowSupport.java b/akka-stream/src/main/java-jdk-9/akka/stream/javadsl/JavaFlowSupport.java
index ef2844c6cd1..2d34e5d25ad 100644
--- a/akka-stream/src/main/java-jdk-9/akka/stream/javadsl/JavaFlowSupport.java
+++ b/akka-stream/src/main/java-jdk-9/akka/stream/javadsl/JavaFlowSupport.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017-2018 Lightbend Inc. <https://www.lightbend.com>
+ * Copyright (C) 2017-2019 Lightbend Inc. <https://www.lightbend.com>
  */
 
 package akka.stream.javadsl;
diff --git a/akka-stream/src/main/scala-jdk-9/akka/stream/impl/JavaFlowAndRsConverters.scala b/akka-stream/src/main/scala-jdk-9/akka/stream/impl/JavaFlowAndRsConverters.scala
index d7ae85b3105..77b260a9c07 100644
--- a/akka-stream/src/main/scala-jdk-9/akka/stream/impl/JavaFlowAndRsConverters.scala
+++ b/akka-stream/src/main/scala-jdk-9/akka/stream/impl/JavaFlowAndRsConverters.scala
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017-2018 Lightbend Inc. <https://www.lightbend.com>
+ * Copyright (C) 2017-2019 Lightbend Inc. <https://www.lightbend.com>
  */
 
 package akka.stream.impl
diff --git a/akka-stream/src/main/scala-jdk-9/akka/stream/scaladsl/JavaFlowSupport.scala b/akka-stream/src/main/scala-jdk-9/akka/stream/scaladsl/JavaFlowSupport.scala
index cf292fdea36..7761b57ea16 100644
--- a/akka-stream/src/main/scala-jdk-9/akka/stream/scaladsl/JavaFlowSupport.scala
+++ b/akka-stream/src/main/scala-jdk-9/akka/stream/scaladsl/JavaFlowSupport.scala
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2017-2018 Lightbend Inc. <https://www.lightbend.com>
+ * Copyright (C) 2017-2019 Lightbend Inc. <https://www.lightbend.com>
  */
 
 package akka.stream.scaladsl
diff --git a/project/CopyrightHeader.scala b/project/CopyrightHeader.scala
index 6d98d1b0099..f955e5828dc 100644
--- a/project/CopyrightHeader.scala
+++ b/project/CopyrightHeader.scala
@@ -15,7 +15,7 @@ trait CopyrightHeader extends AutoPlugin {
 
   override def requires:Plugins = HeaderPlugin
 
-  override def trigger = allRequirements
+  override def trigger: PluginTrigger = allRequirements
 
   protected def headerMappingSettings: Seq[Def.Setting[_]] =
     Seq(Compile, Test, MultiJvm).flatMap { config =>
diff --git a/project/CopyrightHeaderForBoilerplate.scala b/project/CopyrightHeaderForBoilerplate.scala
index 510794d0f7f..4d5d7175c2a 100644
--- a/project/CopyrightHeaderForBoilerplate.scala
+++ b/project/CopyrightHeaderForBoilerplate.scala
@@ -2,7 +2,8 @@
  * Copyright (C) 2019 Lightbend Inc. <https://www.lightbend.com>
  */
 
-import akka.CopyrightHeader
+package akka
+
 import de.heikoseeberger.sbtheader.HeaderPlugin
 import de.heikoseeberger.sbtheader.HeaderPlugin.autoImport._
 import sbt.Keys.sourceDirectory
diff --git a/project/CopyrightHeaderForJdk9.scala b/project/CopyrightHeaderForJdk9.scala
new file mode 100644
index 00000000000..daa1ce80af8
--- /dev/null
+++ b/project/CopyrightHeaderForJdk9.scala
@@ -0,0 +1,28 @@
+/*
+ * Copyright (C) 2019 Lightbend Inc. <https://www.lightbend.com>
+ */
+
+package akka
+
+import de.heikoseeberger.sbtheader.HeaderPlugin.autoImport.headerSources
+import sbt.Keys.sourceDirectory
+import sbt.{Compile, Def, Test, _}
+
+
+object CopyrightHeaderForJdk9 extends CopyrightHeader {
+
+  override protected def headerMappingSettings: Seq[Def.Setting[_]] = {
+    super.headerMappingSettings
+    import Jdk9._
+    Seq(
+      headerSources in Compile ++=
+        (((sourceDirectory in Compile).value / SCALA_SOURCE_DIRECTORY) ** "*.scala").get,
+      headerSources in Test ++=
+        (((sourceDirectory in Test).value / SCALA_TEST_SOURCE_DIRECTORY) ** "*.scala").get,
+      headerSources in Compile ++=
+        (((sourceDirectory in Compile).value / JAVA_SOURCE_DIRECTORY) ** "*.java").get,
+      headerSources in Test ++=
+        (((sourceDirectory in Test).value / JAVA_TEST_SOURCE_DIRECTORY) ** "*.java").get,
+    )
+  }
+}
diff --git a/project/CopyrightHeaderForProtobuf.scala b/project/CopyrightHeaderForProtobuf.scala
index 066ad7acbb7..780af3cd40a 100644
--- a/project/CopyrightHeaderForProtobuf.scala
+++ b/project/CopyrightHeaderForProtobuf.scala
@@ -2,7 +2,8 @@
  * Copyright (C) 2019 Lightbend Inc. <https://www.lightbend.com>
  */
 
-import akka.CopyrightHeader
+package akka
+
 import de.heikoseeberger.sbtheader.HeaderPlugin.autoImport.{HeaderFileType, headerMappings, headerSources}
 import sbt.Keys.sourceDirectory
 import sbt.{Compile, Def, Test, inConfig, _}
diff --git a/project/Jdk9.scala b/project/Jdk9.scala
index ee743f5a2bb..0eb24f26764 100644
--- a/project/Jdk9.scala
+++ b/project/Jdk9.scala
@@ -20,11 +20,16 @@ object Jdk9 extends AutoPlugin {
     if (System.getProperty("java.version").startsWith("1.")) Seq()
     else values
 
+  val SCALA_SOURCE_DIRECTORY = "scala-jdk-9"
+  val SCALA_TEST_SOURCE_DIRECTORY = "scala-jdk9-only"
+  val JAVA_SOURCE_DIRECTORY = "java-jdk-9"
+  val JAVA_TEST_SOURCE_DIRECTORY = "java-jdk9-only"
+  
   val compileJdk9Settings = Seq(
     // following the scala-2.12, scala-sbt-1.0, ... convention
     unmanagedSourceDirectories := notOnJdk8(notOnScala211(scalaBinaryVersion.value, Seq(
-      (Compile / sourceDirectory).value / "scala-jdk-9",
-      (Compile / sourceDirectory).value / "java-jdk-9"
+      (Compile / sourceDirectory).value / SCALA_SOURCE_DIRECTORY,
+      (Compile / sourceDirectory).value / JAVA_SOURCE_DIRECTORY
     ))),
     scalacOptions := AkkaBuild.DefaultScalacOptions ++ notOnJdk8(notOnScala211(scalaBinaryVersion.value, Seq("-release", "9"))),
     javacOptions := AkkaBuild.DefaultJavacOptions ++ notOnJdk8(notOnScala211(scalaBinaryVersion.value, Seq("--release", "9")))