diff --git a/akka-actor/src/main/scala/akka/util/ErrorMessages.scala b/akka-actor/src/main/scala/akka/util/ErrorMessages.scala
index 447cf68af9..0dd21fec55 100644
--- a/akka-actor/src/main/scala/akka/util/ErrorMessages.scala
+++ b/akka-actor/src/main/scala/akka/util/ErrorMessages.scala
@@ -4,6 +4,9 @@
 
 package akka.util
 
-object ErrorMessages {
+/**
+ * INTERNAL API
+ */
+private[akka] object ErrorMessages {
   val RemoteDeploymentConfigErrorPrefix = "configuration requested remote deployment"
 }