src/java.base/share/classes/java/lang/Enum.java

*** 273,287 ****
--- 273,289 ----
      protected final void finalize() { }
  
      /**
       * prevent default deserialization
       */
+     @java.io.Serial
      private void readObject(ObjectInputStream in) throws IOException,
          ClassNotFoundException {
          throw new InvalidObjectException("can't deserialize enum");
      }
  
+     @java.io.Serial
      private void readObjectNoData() throws ObjectStreamException {
          throw new InvalidObjectException("can't deserialize enum");
      }
  
      /**