--- old/src/java.base/share/classes/java/time/chrono/ChronoLocalDateTimeImpl.java	2019-08-27 17:28:36.914324386 -0700
+++ new/src/java.base/share/classes/java/time/chrono/ChronoLocalDateTimeImpl.java	2019-08-27 17:28:36.714324386 -0700
@@ -103,6 +103,7 @@
     /**
      * Serialization version.
      */
+    @java.io.Serial
     private static final long serialVersionUID = 4556003607393004514L;
     /**
      * Hours per day.
@@ -409,6 +410,7 @@
      *
      * @return the instance of {@code Ser}, not null
      */
+   @java.io.Serial
     private Object writeReplace() {
         return new Ser(Ser.CHRONO_LOCAL_DATE_TIME_TYPE, this);
     }
@@ -419,6 +421,7 @@
      * @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");
     }