diff --git a/lib/server.js b/lib/server.js
index 99dfb4150..aeda6a144 100644
--- a/lib/server.js
+++ b/lib/server.js
@@ -278,8 +278,8 @@ function sendErrorMessage (req, res, code) {
  * @api public
  */
 
-Server.prototype.generateId = function (req) {
-  return base64id.generateId();
+Server.prototype.generateId = function (req, done) {
+  done(base64id.generateId());
 };
 
 /**
@@ -291,52 +291,53 @@ Server.prototype.generateId = function (req) {
  */
 
 Server.prototype.handshake = function (transportName, req) {
-  var id = this.generateId(req);
-
-  debug('handshaking client "%s"', id);
+  var self = this;
+  var this_ = this;
+  this.generateId(req, function (id) {
+    debug('handshaking client "%s"', id);
+
+    try {
+      var transport = new transports[transportName](req);
+      if ('polling' === transportName) {
+        transport.maxHttpBufferSize = this_.maxHttpBufferSize;
+        transport.httpCompression = this_.httpCompression;
+      } else if ('websocket' === transportName) {
+        transport.perMessageDeflate = this_.perMessageDeflate;
+      }
 
-  try {
-    var transport = new transports[transportName](req);
-    if ('polling' === transportName) {
-      transport.maxHttpBufferSize = this.maxHttpBufferSize;
-      transport.httpCompression = this.httpCompression;
-    } else if ('websocket' === transportName) {
-      transport.perMessageDeflate = this.perMessageDeflate;
+      if (req._query && req._query.b64) {
+        transport.supportsBinary = false;
+      } else {
+        transport.supportsBinary = true;
+      }
+    } catch (e) {
+      sendErrorMessage(req, req.res, Server.errors.BAD_REQUEST);
+      return;
     }
-
-    if (req._query && req._query.b64) {
-      transport.supportsBinary = false;
-    } else {
-      transport.supportsBinary = true;
+    var socket = new Socket(id, this_, transport, req);
+
+    if (false !== this.cookie) {
+      transport.on('headers', function (headers) {
+        headers['Set-Cookie'] = cookieMod.serialize(self.cookie, id,
+          {
+            path: self.cookiePath,
+            httpOnly: self.cookiePath ? self.cookieHttpOnly : false
+          });
+      });
     }
-  } catch (e) {
-    sendErrorMessage(req, req.res, Server.errors.BAD_REQUEST);
-    return;
-  }
-  var socket = new Socket(id, this, transport, req);
-  var self = this;
 
-  if (false !== this.cookie) {
-    transport.on('headers', function (headers) {
-      headers['Set-Cookie'] = cookieMod.serialize(self.cookie, id,
-        {
-          path: self.cookiePath,
-          httpOnly: self.cookiePath ? self.cookieHttpOnly : false
-        });
-    });
-  }
+    transport.onRequest(req);
 
-  transport.onRequest(req);
+    this.clients[id] = socket;
+    this.clientsCount++;
 
-  this.clients[id] = socket;
-  this.clientsCount++;
+    socket.once('close', function () {
+      delete self.clients[id];
+      self.clientsCount--;
+    });
 
-  socket.once('close', function () {
-    delete self.clients[id];
-    self.clientsCount--;
+    this.emit('connection', socket);
   });
-
-  this.emit('connection', socket);
 };
 
 /**