--- old/src/java.base/share/classes/java/util/AbstractMap.java	2019-08-27 17:28:46.550324386 -0700
+++ new/src/java.base/share/classes/java/util/AbstractMap.java	2019-08-27 17:28:46.386324386 -0700
@@ -604,6 +604,7 @@
     public static class SimpleEntry<K,V>
         implements Entry<K,V>, java.io.Serializable
     {
+        @java.io.Serial
         private static final long serialVersionUID = -8499721149061103585L;
 
         private final K key;
@@ -734,6 +735,7 @@
     public static class SimpleImmutableEntry<K,V>
         implements Entry<K,V>, java.io.Serializable
     {
+        @java.io.Serial
         private static final long serialVersionUID = 7138329143949025153L;
 
         private final K key;