--- old/src/java.base/share/classes/java/util/IllegalFormatWidthException.java	2019-08-27 17:29:01.938324386 -0700
+++ new/src/java.base/share/classes/java/util/IllegalFormatWidthException.java	2019-08-27 17:29:01.750324386 -0700
@@ -33,6 +33,7 @@
  */
 public class IllegalFormatWidthException extends IllegalFormatException {
 
+    @java.io.Serial
     private static final long serialVersionUID = 16660902L;
 
     private int w;