--- a/src/java.base/share/classes/java/security/Timestamp.java	Thu Aug 29 10:09:27 2019 -0700
+++ b/src/java.base/share/classes/java/security/Timestamp.java	Thu Aug 29 10:52:21 2019 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2011, 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
@@ -44,6 +44,7 @@
 
 public final class Timestamp implements Serializable {
 
+    @java.io.Serial
     private static final long serialVersionUID = -5502683707821851294L;
 
     /**
@@ -155,6 +156,7 @@
     }
 
     // Explicitly reset hash code value to -1
+    @java.io.Serial
     private void readObject(ObjectInputStream ois)
         throws IOException, ClassNotFoundException {
         ois.defaultReadObject();