src/java.base/share/classes/java/util/regex/PatternSyntaxException.java

@@ -35,10 +35,11 @@
  */
 
 public class PatternSyntaxException
     extends IllegalArgumentException
 {
+    @java.io.Serial
     private static final long serialVersionUID = -3864639126226059218L;
 
     private final String desc;
     private final String pattern;
     private final int index;