src/java.base/share/classes/java/net/UnknownServiceException.java

@@ -35,10 +35,11 @@
  *
  * @author  unascribed
  * @since   1.0
  */
 public class UnknownServiceException extends IOException {
+    @java.io.Serial
     private static final long serialVersionUID = -4169033248853639508L;
 
     /**
      * Constructs a new {@code UnknownServiceException} with no
      * detail message.