src/java.base/share/classes/java/util/MissingFormatWidthException.java

@@ -34,10 +34,11 @@
  *
  * @since 1.5
  */
 public class MissingFormatWidthException extends IllegalFormatException {
 
+    @java.io.Serial
     private static final long serialVersionUID = 15560123L;
 
     private String s;
 
     /**