diff -r 18863bf3501f -r e0b8b019d2f5 src/java.base/share/classes/java/text/DecimalFormat.java
--- a/src/java.base/share/classes/java/text/DecimalFormat.java	Thu Aug 29 18:52:30 2019 -0400
+++ b/src/java.base/share/classes/java/text/DecimalFormat.java	Thu Aug 29 16:31:34 2019 -0700
@@ -3870,6 +3870,7 @@
      * literal values.  This is exactly what we want, since that corresponds to
      * the pre-version-2 behavior.
      */
+    @java.io.Serial
     private void readObject(ObjectInputStream stream)
          throws IOException, ClassNotFoundException
     {
@@ -4343,5 +4344,6 @@
     static final int MAXIMUM_FRACTION_DIGITS = Integer.MAX_VALUE;
 
     // Proclaim JDK 1.1 serial compatibility.
+    @java.io.Serial
     static final long serialVersionUID = 864413376551465018L;
 }