--- old/src/java.base/share/classes/java/net/ConnectException.java	2019-08-27 17:27:56.662324386 -0700
+++ new/src/java.base/share/classes/java/net/ConnectException.java	2019-08-27 17:27:56.458324386 -0700
@@ -34,6 +34,7 @@
  * @since   1.1
  */
 public class ConnectException extends SocketException {
+    @java.io.Serial
     private static final long serialVersionUID = 3831404271622369215L;
 
     /**