src/java.base/share/classes/java/util/AbstractMap.java

@@ -602,10 +602,11 @@
      * @since 1.6
      */
     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;
         private V value;
 

@@ -732,10 +733,11 @@
      * @since 1.6
      */
     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;
         private final V value;