diff --git a/akka-http-core/src/main/scala/akka/http/Http.scala b/akka-http-core/src/main/scala/akka/http/Http.scala
index a108634900..ea56d67c3b 100644
--- a/akka-http-core/src/main/scala/akka/http/Http.scala
+++ b/akka-http-core/src/main/scala/akka/http/Http.scala
@@ -91,7 +91,7 @@ object Http extends ExtensionId[HttpExt] with ExtensionIdProvider {
   /**
    * Represents a prospective HTTP server binding.
    */
-  trait ServerBinding {
+  sealed trait ServerBinding {
     /**
      * The local address of the endpoint bound by the materialization of the `connections` [[Source]]
      * whose [[MaterializedMap]] is passed as parameter.