--- old/src/java.base/share/classes/java/time/LocalDateTime.java	2019-08-27 17:28:28.670324386 -0700
+++ new/src/java.base/share/classes/java/time/LocalDateTime.java	2019-08-27 17:28:28.466324386 -0700
@@ -153,6 +153,7 @@
     /**
      * Serialization version.
      */
+    @java.io.Serial
     private static final long serialVersionUID = 6207766400415563566L;
 
     /**
@@ -1985,6 +1986,7 @@
      *
      * @return the instance of {@code Ser}, not null
      */
+    @java.io.Serial
     private Object writeReplace() {
         return new Ser(Ser.LOCAL_DATE_TIME_TYPE, this);
     }
@@ -1995,6 +1997,7 @@
      * @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");
     }