--- a/test/jdk/com/sun/net/httpserver/Test12.java	Mon Jun 10 10:11:42 2019 +0100
+++ b/test/jdk/com/sun/net/httpserver/Test12.java	Tue Jun 11 15:46:26 2019 +0100
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,7 @@
  * @library /test/lib
  * @build jdk.test.lib.net.SimpleSSLContext
  * @run main/othervm Test12
+ * @run main/othervm -Djava.net.preferIPv6Addresses=true Test12
  * @summary Light weight HTTP server
  */
 
@@ -37,6 +38,7 @@
 import java.net.*;
 import javax.net.ssl.*;
 import jdk.test.lib.net.SimpleSSLContext;
+import jdk.test.lib.net.URIBuilder;
 
 /* basic http/s connectivity test
  * Tests:
@@ -56,7 +58,8 @@
         try {
             String root = System.getProperty ("test.src")+ "/docs";
             System.out.print ("Test12: ");
-            InetSocketAddress addr = new InetSocketAddress (0);
+            InetAddress loopback = InetAddress.getLoopbackAddress();
+            InetSocketAddress addr = new InetSocketAddress(loopback, 0);
             s1 = HttpServer.create (addr, 0);
             s2 = HttpsServer.create (addr, 0);
             HttpHandler h = new FileServerHandler (root);
@@ -130,8 +133,13 @@
 
         public void run () {
             try {
-                URL url = new URL (protocol+"://localhost:"+port+"/test1/"+f);
-                HttpURLConnection urlc = (HttpURLConnection) url.openConnection();
+                URL url = URIBuilder.newBuilder()
+                          .scheme(protocol)
+                          .loopback()
+                          .port(port)
+                          .path("/test1/"+f)
+                          .toURL();
+                HttpURLConnection urlc = (HttpURLConnection) url.openConnection(Proxy.NO_PROXY);
                 if (urlc instanceof HttpsURLConnection) {
                     HttpsURLConnection urlcs = (HttpsURLConnection) urlc;
                     urlcs.setHostnameVerifier (new HostnameVerifier () {