diff --git a/.zuul.yml b/.zuul.yml
index 6cf6dad7..e38b404b 100644
--- a/.zuul.yml
+++ b/.zuul.yml
@@ -5,5 +5,4 @@ tunnel:
   authtoken: 6Aw8vTgcG5EvXdQywVvbh_3fMxvd4Q7dcL2caAHAFjV
   proto: tcp
 browserify:
-  - exclude: bufferutil
-  - exclude: utf-8-validate
+  - ignore: ws
diff --git a/README.md b/README.md
index 2cdcbecb..19d31491 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,7 @@ Engine.IO is a commonjs module, which means you can include it by using
 1. build your app bundle
 
     ```bash
-    $ browserify app.js > bundle.js
+    $ browserify app.js -i ws > bundle.js
     ```
 
 1. include on your page
diff --git a/lib/transports/websocket.js b/lib/transports/websocket.js
index f2784658..2f0e45ee 100644
--- a/lib/transports/websocket.js
+++ b/lib/transports/websocket.js
@@ -8,6 +8,7 @@ var parseqs = require('parseqs');
 var inherit = require('component-inherit');
 var yeast = require('yeast');
 var debug = require('debug')('engine.io-client:websocket');
+var BrowserWebSocket = global.WebSocket || global.MozWebSocket;
 
 /**
  * Get either the `WebSocket` or `MozWebSocket` globals
@@ -15,7 +16,7 @@ var debug = require('debug')('engine.io-client:websocket');
  * exposed by `ws` for Node environment.
  */
 
-var WebSocket = typeof window !== 'undefined' ? (window.WebSocket || window.MozWebSocket) : require('ws');
+var WebSocket = BrowserWebSocket || (typeof window !== 'undefined' ? null : require('ws'));
 
 /**
  * Module exports.
@@ -91,7 +92,7 @@ WS.prototype.doOpen = function(){
     opts.headers = this.extraHeaders;
   }
 
-  this.ws = new WebSocket(uri, protocols, opts);
+  this.ws = BrowserWebSocket ? new WebSocket(uri) : new WebSocket(uri, protocols, opts);
 
   if (this.ws.binaryType === undefined) {
     this.supportsBinary = false;
@@ -158,15 +159,13 @@ WS.prototype.write = function(packets){
   var self = this;
   this.writable = false;
 
-  var isBrowserWebSocket = global.WebSocket && this.ws instanceof global.WebSocket;
-
   // encodePacket efficient as it uses WS framing
   // no need for encodePayload
   var total = packets.length;
   for (var i = 0, l = total; i < l; i++) {
     (function(packet) {
       parser.encodePacket(packet, self.supportsBinary, function(data) {
-        if (!isBrowserWebSocket) {
+        if (!BrowserWebSocket) {
           // always create a new object (GH-437)
           var opts = {};
           if (packet.options) {
@@ -185,7 +184,7 @@ WS.prototype.write = function(packets){
         //have a chance of informing us about it yet, in that case send will
         //throw an error
         try {
-          if (isBrowserWebSocket) {
+          if (BrowserWebSocket) {
             // TypeError is thrown when passing the second argument on Safari
             self.ws.send(data);
           } else {
diff --git a/support/browserify.js b/support/browserify.js
index ad976a4c..9126a9db 100644
--- a/support/browserify.js
+++ b/support/browserify.js
@@ -28,8 +28,7 @@ function build(fn){
     insertGlobalVars: { global: glob },
     standalone: 'eio'
   })
-  .exclude('bufferutil')
-  .exclude('utf-8-validate')
+  .ignore('ws')
   .bundle();
 
   bundle.on('error', function (err) {
diff --git a/test/support/env.js b/test/support/env.js
index ce1408c8..3551fa45 100644
--- a/test/support/env.js
+++ b/test/support/env.js
@@ -3,7 +3,7 @@
 // support in browsers and in node.js
 // some tests do not yet work in both
 exports.browser = !!global.window;
-exports.wsSupport = !!require('ws');
+exports.wsSupport = !!(!global.window || window.WebSocket || window.MozWebSocket);
 
 var userAgent = global.navigator ? navigator.userAgent : '';
 exports.isOldSimulator = ~userAgent.indexOf('iPhone OS 4') || ~userAgent.indexOf('iPhone OS 5');