--- old/src/java.base/share/classes/java/time/chrono/HijrahDate.java	2019-08-27 17:28:39.082324386 -0700
+++ new/src/java.base/share/classes/java/time/chrono/HijrahDate.java	2019-08-27 17:28:38.898324386 -0700
@@ -123,6 +123,7 @@
     /**
      * Serialization version.
      */
+    @java.io.Serial
     private static final long serialVersionUID = -5207853542612002020L;
     /**
      * The Chronology of this HijrahDate.
@@ -657,6 +658,7 @@
      * @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");
     }
@@ -675,6 +677,7 @@
      *
      * @return the instance of {@code Ser}, not null
      */
+    @java.io.Serial
     private Object writeReplace() {
         return new Ser(Ser.HIJRAH_DATE_TYPE, this);
     }