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

*** 203,212 ****
--- 203,213 ----
       */
      private final transient String calendarType;
      /**
       * Serialization version.
       */
+     @java.io.Serial
      private static final long serialVersionUID = 3127340209035924785L;
      /**
       * Singleton instance of the Islamic Umm Al-Qura calendar of Saudi Arabia.
       * Other Hijrah chronology variants may be available from
       * {@link Chronology#getAvailableChronologies}.
*** 1019,1037 ****
--- 1020,1040 ----
       * </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");
      }
  }