--- old/src/java.rmi/share/classes/java/rmi/activation/ActivationGroup.java	2019-10-15 11:20:19.608911043 -0700
+++ new/src/java.rmi/share/classes/java/rmi/activation/ActivationGroup.java	2019-10-15 11:20:19.424911043 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -107,6 +107,7 @@
     /**
      * @serial the group's monitor
      */
+    @SuppressWarnings("serial") // Not statically typed as Serializable
     private ActivationMonitor monitor;
 
     /**