diff --git a/package.json b/package.json
index 867ae9e52..716de18bd 100644
--- a/package.json
+++ b/package.json
@@ -16,9 +16,10 @@
     "extendable": ">=0.0.3",
     "hashy": ">=0.1.0",
     "q": ">=0.9.6",
-    "socket.io": ">=0.9.16",
+    "sync": ">=0.2.2",
     "underscore": ">=1.4.4",
     "validator": ">=1.2.1",
+    "ws": ">=0.4.27",
     "xmlrpc": ">=1.1.0"
   },
   "devDependencies": {},
diff --git a/src/main.js b/src/main.js
index ae5fa339c..b39c991ce 100644
--- a/src/main.js
+++ b/src/main.js
@@ -80,25 +80,24 @@ function json_api_call(session, message)
 //////////////////////////////////////////////////////////////////////
 
  // @todo Port should be configurable.
-require('socket.io').listen(8080, {'log level': 0}).sockets
-	.on('connection', function (socket) {
-		var session = new Session(xo);
-		session.once('close', function () {
-			socket.disconnect();
-		});
-
-		socket.on('message', function (request) {
-			json_api_call(session, request).then(function (response) {
-				socket.send(response);
-			}).done();
-		});
-
-		// @todo Ugly inter dependency.
-		socket.once('disconnect', function () {
-			session.close();
-		});
+new (require('ws').Server)({'port': 8080}).on('connection', function (socket) {
+	var session = new Session(xo);
+	session.once('close', function () {
+		socket.close();
 	});
 
+	socket.on('message', function (request) {
+		json_api_call(session, request).then(function (response) {
+			socket.send(response);
+		}).done();
+	});
+
+	// @todo Ugly inter dependency.
+	socket.once('close', function () {
+		session.close();
+	});
+});
+
 //////////////////////////////////////////////////////////////////////
 // JSON-RPC over TCP.
 //////////////////////////////////////////////////////////////////////
diff --git a/tests/websocket.js b/tests/websocket.js
new file mode 100644
index 000000000..8001545e3
--- /dev/null
+++ b/tests/websocket.js
@@ -0,0 +1,148 @@
+/* jshint loopfunc:false */
+
+var assert = require('assert');
+var sync = require('sync');
+var WS = require('ws');
+
+//////////////////////////////////////////////////////////////////////
+
+var tests = {
+
+	'Session management': {
+
+		'Password sign in': function () {
+			var conn = this.connect('ws://localhost:8080/');
+			assert(conn('session.signInWithPassword', {
+				'email': 'bob@gmail.com',
+				'password': '123',
+			}));
+		},
+
+		'Token sign in': function () {
+			assert(false);
+		},
+
+		'Connection close out when token removed': function () {
+			// Connects, signs in (with a password) and creates a token.
+			var conn = this.connect('ws://localhost:8080/');
+			conn('session.signInWithPassword', {
+				'email': 'bob@gmail.com',
+				'password': '123',
+			});
+			var token = conn('token.create');
+
+			// Connects again and uses the token to sign in.
+			var conn2 = this.connect('ws://localhost:8080');
+			conn2('session.signInWithToken', {'token': token});
+
+			// Delete the tokens.
+			conn('token.delete', {'token': token});
+
+			// Checks the second connection is closed.
+			assert.throws(function () {
+				conn2('session.getUserId');
+			});
+
+			// Checks the first connection is still opened.
+			conn('session.getUserId');
+		},
+	},
+
+};
+
+//////////////////////////////////////////////////////////////////////
+
+var next_id = 0;
+function call(method, params)
+{
+	return function (callback)
+	{
+		var request = {
+			'jsonrpc': '2.0',
+			'id': next_id++,
+			'method': method,
+			'params': params || {},
+		};
+		this.send(JSON.stringify(request), function (error) {
+			if (error)
+			{
+				callback(error);
+			}
+		});
+
+		this.once('message', function (response) {
+			try
+			{
+				response = JSON.parse(response.toString());
+			}
+			catch (e)
+			{
+				callback(e);
+				return;
+			}
+
+			if (response.error)
+			{
+				// To help find the problem, the request is included
+				// in the error.
+				var error = response.error;
+				error.request = request;
+
+				callback(error);
+				return;
+			}
+
+			callback(null, response.result);
+		});
+	}.sync(this);
+}
+
+function connect(url)
+{
+	var socket;
+
+	(function (callback)
+	{
+		socket = new WS(url);
+		socket.on('open', function () {
+			callback(null, socket);
+		});
+		socket.on('error', function (error) {
+			callback(error);
+		});
+	}).sync();
+
+	var conn = function (method, params) {
+		return call.call(socket, method, params);
+	};
+	return conn;
+}
+
+//////////////////////////////////////////////////////////////////////
+
+sync(function () {
+	for (var category in tests)
+	{
+		console.log(category);
+		console.log('====================');
+
+		for (var test in tests[category])
+		{
+			console.log('- '+ test);
+
+			var f = tests[category][test];
+			try
+			{
+				f.call({
+					'connect': connect,
+				});
+			}
+			catch (error)
+			{
+				console.error(error);
+			}
+		}
+	}
+}, function () {
+	process.exit();
+});