--- old/src/java.base/share/classes/java/time/MonthDay.java	2019-08-27 17:28:29.810324386 -0700
+++ new/src/java.base/share/classes/java/time/MonthDay.java	2019-08-27 17:28:29.622324386 -0700
@@ -130,6 +130,7 @@
     /**
      * Serialization version.
      */
+    @java.io.Serial
     private static final long serialVersionUID = -939150713474957432L;
     /**
      * Parser.
@@ -764,6 +765,7 @@
      *
      * @return the instance of {@code Ser}, not null
      */
+    @java.io.Serial
     private Object writeReplace() {
         return new Ser(Ser.MONTH_DAY_TYPE, this);
     }
@@ -774,6 +776,7 @@
      * @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");
     }