src/java.base/share/classes/sun/net/TelnetProtocolException.java

@@ -33,10 +33,11 @@
  *
  * @author      Jonathan Payne
  */
 
 public class TelnetProtocolException extends IOException {
+    @java.io.Serial
     private static final long serialVersionUID = 8509127047257111343L;
 
     public TelnetProtocolException(String s) {
         super(s);
     }