--- old/src/java.base/share/classes/java/text/DateFormatSymbols.java	2019-08-27 17:28:21.594324386 -0700
+++ new/src/java.base/share/classes/java/text/DateFormatSymbols.java	2019-08-27 17:28:21.410324386 -0700
@@ -290,6 +290,7 @@
     Locale locale = null;
 
     /* use serialVersionUID from JDK 1.1.4 for interoperability */
+    @java.io.Serial
     static final long serialVersionUID = -5987973545549424702L;
 
     /**
@@ -892,6 +893,7 @@
      *
      * @since 1.6
      */
+    @java.io.Serial
     private void writeObject(ObjectOutputStream stream) throws IOException {
         if (zoneStrings == null) {
             zoneStrings = TimeZoneNameUtility.getZoneStrings(locale);