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

@@ -121,10 +121,11 @@
         implements ChronoLocalDate, Serializable {
 
     /**
      * Serialization version.
      */
+    @java.io.Serial
     private static final long serialVersionUID = -5207853542612002020L;
     /**
      * The Chronology of this HijrahDate.
      */
     private final transient HijrahChronology chrono;

@@ -655,10 +656,11 @@
      * 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");
     }
 
     /**

@@ -673,10 +675,11 @@
      *  out.writeByte(get(DAY_OF_MONTH));
      * </pre>
      *
      * @return the instance of {@code Ser}, not null
      */
+    @java.io.Serial
     private Object writeReplace() {
         return new Ser(Ser.HIJRAH_DATE_TYPE, this);
     }
 
     void writeExternal(ObjectOutput out) throws IOException {