diff --git a/tests/wpt/web-platform-tests/websockets/constants.js b/tests/wpt/web-platform-tests/websockets/constants.js
index f7d46d2c44e..8312cd253fe 100644
--- a/tests/wpt/web-platform-tests/websockets/constants.js
+++ b/tests/wpt/web-platform-tests/websockets/constants.js
@@ -1,18 +1,12 @@
-//This file requires server-side substitutions and must be included as constants.js?pipe=config
-var DOMAIN_FOR_WS_TESTS = "{{host}}";
-var DOMAIN_FOR_WSS_TESTS = "{{host}}";
+//This file requires server-side substitutions and must be included as constants.js?pipe=sub
 
 var PORT = "{{ports[ws][0]}}";
 //FIXME: Add support for wss
 var PORT_SSL = "{{ports[ws][0]}}";
 
-// logic for using wss URLs instead of ws
-var SCHEME_AND_DOMAIN;
 var SCHEME_DOMAIN_PORT;
 if (location.search == '?wss') {
-  SCHEME_AND_DOMAIN = 'wss://'+DOMAIN_FOR_WSS_TESTS;
-  SCHEME_DOMAIN_PORT = SCHEME_AND_DOMAIN + ":" + PORT_SSL;
+  SCHEME_DOMAIN_PORT = 'wss://{{host}}:' + PORT_SSL;
 } else {
-  SCHEME_AND_DOMAIN = 'ws://'+DOMAIN_FOR_WS_TESTS;
-  SCHEME_DOMAIN_PORT = SCHEME_AND_DOMAIN + ":" + PORT;
+  SCHEME_DOMAIN_PORT = 'ws://{{host}}:' + PORT;
 }
diff --git a/tests/wpt/web-platform-tests/websockets/constructor/002.html b/tests/wpt/web-platform-tests/websockets/constructor/002.html
index 956cb1e9248..1acc2dbb82e 100644
--- a/tests/wpt/web-platform-tests/websockets/constructor/002.html
+++ b/tests/wpt/web-platform-tests/websockets/constructor/002.html
@@ -11,8 +11,8 @@ test(function() {assert_throws("SyntaxError", function(){new WebSocket("wss://fo
 test(function() {assert_throws("SyntaxError", function(){new WebSocket("http://"+location.host+"/")})});
 test(function() {assert_throws("SyntaxError", function(){new WebSocket("mailto:example@example.org")})});
 test(function() {assert_throws("SyntaxError", function(){new WebSocket("about:blank")})});
-test(function() {assert_throws("SyntaxError", function(){new WebSocket("ws://"+location.host+"/#")})});
-test(function() {assert_throws("SyntaxError", function(){new WebSocket("ws://"+location.host+"/#test")})});
+test(function() {assert_throws("SyntaxError", function(){new WebSocket(SCHEME_DOMAIN_PORT+"/#")})});
+test(function() {assert_throws("SyntaxError", function(){new WebSocket(SCHEME_DOMAIN_PORT+"/#test")})});
 test(function() {assert_throws("SyntaxError", function(){new WebSocket("?test")})});
 test(function() {assert_throws("SyntaxError", function(){new WebSocket("#test")})});
 </script>
diff --git a/tests/wpt/web-platform-tests/websockets/constructor/004.html b/tests/wpt/web-platform-tests/websockets/constructor/004.html
index a58fb3720ac..042caa1e589 100644
--- a/tests/wpt/web-platform-tests/websockets/constructor/004.html
+++ b/tests/wpt/web-platform-tests/websockets/constructor/004.html
@@ -6,18 +6,28 @@
 <div id=log></div>
 <script>
 // empty string
-test(function() {assert_throws("SyntaxError", function(){new WebSocket("ws://"+location.host+"/", "")})});
+test(function() {
+  assert_throws("SyntaxError", function() {
+    new WebSocket(SCHEME_DOMAIN_PORT + '/empty-message', "")
+  })
+});
 
 // chars below U+0020 except U+0000; U+0000 is tested in a separate test
 for (var i = 1; i < 0x20; ++i) {
-test(function() {
-  assert_throws("SyntaxError", function(){new WebSocket("ws://"+location.host+"/", "a"+String.fromCharCode(i)+"b")}, 'char code '+i);
-})
+  test(function() {
+    assert_throws("SyntaxError", function() {
+      new WebSocket(SCHEME_DOMAIN_PORT + '/empty-message',
+                    "a"+String.fromCharCode(i)+"b")
+    }, 'char code '+i);
+  })
 }
 // some chars above U+007E
 for (var i = 0x7F; i < 0x100; ++i) {
-test(function() {
-  assert_throws("SyntaxError", function(){new WebSocket("ws://"+location.host+"/", "a"+String.fromCharCode(i)+"b")}, 'char code '+i);
-})
+  test(function() {
+    assert_throws("SyntaxError", function() {
+      new WebSocket(SCHEME_DOMAIN_PORT + '/empty-message',
+                    "a"+String.fromCharCode(i)+"b")
+    }, 'char code '+i);
+  })
 }
 </script>
diff --git a/tests/wpt/web-platform-tests/websockets/constructor/005.html b/tests/wpt/web-platform-tests/websockets/constructor/005.html
index bb4d6d0f29a..58878b8a5fb 100644
--- a/tests/wpt/web-platform-tests/websockets/constructor/005.html
+++ b/tests/wpt/web-platform-tests/websockets/constructor/005.html
@@ -6,6 +6,6 @@
 <div id=log></div>
 <script>
 test(function() {
-  assert_true(new WebSocket("ws://"+location.host+"/") instanceof WebSocket);
+  assert_true(new WebSocket(SCHEME_DOMAIN_PORT + '/empty-message') instanceof WebSocket);
 });
 </script>
diff --git a/tests/wpt/web-platform-tests/websockets/constructor/007.html b/tests/wpt/web-platform-tests/websockets/constructor/007.html
index a3985cdcc6b..9fcb07dc4d3 100644
--- a/tests/wpt/web-platform-tests/websockets/constructor/007.html
+++ b/tests/wpt/web-platform-tests/websockets/constructor/007.html
@@ -5,5 +5,10 @@
 <script src=../constants.js?pipe=sub></script>
 <div id=log></div>
 <script>
-test(function() {assert_throws("SyntaxError", function(){new WebSocket("ws://"+location.host+"/", 'a'+String.fromCharCode(0)+'b')})});
+test(function() {
+  assert_throws("SyntaxError", function() {
+    new WebSocket(SCHEME_DOMAIN_PORT + '/empty-message',
+                  'a' + String.fromCharCode(0) + 'b')
+  })
+});
 </script>
diff --git a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/010.html b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/010.html
index 367c36c7940..61a184a3dca 100644
--- a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/010.html
+++ b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/010.html
@@ -8,7 +8,7 @@
 var events = ['onclose', 'onopen', 'onerror', 'onmessage'];
 for (var i = 0; i < events.length; ++i) {
   test(function(){
-    var ws = new WebSocket(SCHEME_AND_DOMAIN+'/');
+    var ws = new WebSocket(SCHEME_DOMAIN_PORT+'/empty-message');
     var foo = function() {}
     ws[events[i]] = foo;
     assert_equals(ws[events[i]], foo, events[i]);
diff --git a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/011.html b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/011.html
index a0043ed6456..13a506ddbc9 100644
--- a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/011.html
+++ b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/011.html
@@ -8,7 +8,7 @@
 var events = ['onclose', 'onopen', 'onerror', 'onmessage'];
 for (var i = 0; i < events.length; ++i) {
   test(function(t) {
-    var ws = new WebSocket(SCHEME_AND_DOMAIN+'/');
+    var ws = new WebSocket(SCHEME_DOMAIN_PORT+'/empty-message');
     ws[events[i]] = 1;
     assert_equals(ws[events[i]], null);
   }, events[i]);
diff --git a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/012.html b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/012.html
index 8a507d37808..54500aa7de5 100644
--- a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/012.html
+++ b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/012.html
@@ -8,7 +8,7 @@
 var events = ['onclose', 'onopen', 'onerror', 'onmessage'];
 for (var i = 0; i < events.length; ++i) {
   test(function(t) {
-    var ws = new WebSocket(SCHEME_AND_DOMAIN+'/');
+    var ws = new WebSocket(SCHEME_DOMAIN_PORT+'/empty-message');
     ws[events[i]] = ";";
     assert_equals(ws[events[i]], null);
   }, events[i]);
diff --git a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/013.html b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/013.html
index 719de840a53..e1d93770ad9 100644
--- a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/013.html
+++ b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/013.html
@@ -8,7 +8,7 @@
 var events = ['onclose', 'onopen', 'onerror', 'onmessage'];
 for (var i = 0; i < events.length; ++i) {
   test(function(t) {
-    var ws = new WebSocket(SCHEME_AND_DOMAIN+'/');
+    var ws = new WebSocket(SCHEME_DOMAIN_PORT+'/empty-message');
     var obj = {handleEvent:this.unreached_func("handleEvent was called")};
     ws[events[i]] = obj;
     assert_equals(ws[events[i]], obj);
diff --git a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/014.html b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/014.html
index 92304a600be..81c25484cb0 100644
--- a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/014.html
+++ b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/events/014.html
@@ -8,7 +8,7 @@
 var events = ['onclose', 'onopen', 'onerror', 'onmessage'];
 for (var i = 0; i < events.length; ++i) {
   test(function() {
-    var ws = new WebSocket(SCHEME_AND_DOMAIN+'/');
+    var ws = new WebSocket(SCHEME_DOMAIN_PORT+'/empty-message');
     var foo = function() {}
     ws[events[i]] = foo;
     assert_equals(ws[events[i]], foo, events[i]);
diff --git a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/protocol/protocol-initial.html b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/protocol/protocol-initial.html
index f89c1f05815..4450401f945 100644
--- a/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/protocol/protocol-initial.html
+++ b/tests/wpt/web-platform-tests/websockets/interfaces/WebSocket/protocol/protocol-initial.html
@@ -7,6 +7,6 @@
 <script>
 test(function(t) {
   // The protocol attribute must initially return the empty string
-  assert_equals((new WebSocket(SCHEME_AND_DOMAIN+'/')).protocol, '');
+  assert_equals((new WebSocket(SCHEME_DOMAIN_PORT + '/empty-message')).protocol, '');
 });
 </script>