diff -r 18863bf3501f -r e0b8b019d2f5 src/java.base/share/classes/java/util/EnumMap.java
--- a/src/java.base/share/classes/java/util/EnumMap.java	Thu Aug 29 18:52:30 2019 -0400
+++ b/src/java.base/share/classes/java/util/EnumMap.java	Thu Aug 29 16:31:34 2019 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 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
@@ -754,6 +754,7 @@
                                         .getEnumConstantsShared(keyType);
     }
 
+    @java.io.Serial
     private static final long serialVersionUID = 458661240069192865L;
 
     /**
@@ -765,6 +766,7 @@
      *             and value (Object) for each key-value mapping represented
      *             by the enum map.
      */
+    @java.io.Serial
     private void writeObject(java.io.ObjectOutputStream s)
         throws java.io.IOException
     {
@@ -790,6 +792,7 @@
      * deserialize it).
      */
     @SuppressWarnings("unchecked")
+    @java.io.Serial
     private void readObject(java.io.ObjectInputStream s)
         throws java.io.IOException, ClassNotFoundException
     {