src/java.base/share/classes/java/time/chrono/JapaneseChronology.java

@@ -133,10 +133,11 @@
     public static final JapaneseChronology INSTANCE = new JapaneseChronology();
 
     /**
      * Serialization version.
      */
+    @java.io.Serial
     private static final long serialVersionUID = 459996390165777884L;
 
     //-----------------------------------------------------------------------
     /**
      * Restricted constructor.

@@ -514,19 +515,21 @@
      * </pre>
      *
      * @return the instance of {@code Ser}, not null
      */
     @Override
+    @java.io.Serial
     Object writeReplace() {
         return super.writeReplace();
     }
 
     /**
      * Defend against malicious streams.
      *
      * @param s the stream to read
      * @throws InvalidObjectException always
      */
+    @java.io.Serial
     private void readObject(ObjectInputStream s) throws InvalidObjectException {
         throw new InvalidObjectException("Deserialization via serialization delegate");
     }
 }