--- old/src/java.base/share/classes/java/util/IllegalFormatException.java	2019-08-27 17:29:00.482324386 -0700
+++ new/src/java.base/share/classes/java/util/IllegalFormatException.java	2019-08-27 17:29:00.314324386 -0700
@@ -35,6 +35,7 @@
  */
 public class IllegalFormatException extends IllegalArgumentException {
 
+    @java.io.Serial
     private static final long serialVersionUID = 18830826L;
 
     // package-private to prevent explicit instantiation