--- old/src/java.base/share/classes/sun/util/locale/LocaleSyntaxException.java	2019-08-27 17:29:39.410324386 -0700
+++ new/src/java.base/share/classes/sun/util/locale/LocaleSyntaxException.java	2019-08-27 17:29:39.222324386 -0700
@@ -33,6 +33,7 @@
 
 public class LocaleSyntaxException extends Exception {
 
+    @java.io.Serial
     private static final long serialVersionUID = 1L;
 
     private int index = -1;