diff --git a/lib/x11/xcore.js b/lib/x11/xcore.js
index 3ab66ee..4a2ace1 100644
--- a/lib/x11/xcore.js
+++ b/lib/x11/xcore.js
@@ -329,7 +329,7 @@ module.exports.createClient = function(initCb, display)
     var defaultTransportName = platformDefaultTransport[process.platform];
     // use tcp if stated explicitly or if not defined at all
     if (!defaultTransportName || defaultTransportName == 'tcp' || host != '127.0.0.1')
-        stream = net.createConnection(6000 + displayNum, host);
+        stream = net.createConnection(6000 + parseInt(displayNum), host);
     if (defaultTransportName == 'unix' && host == '127.0.0.1')
         stream = net.createConnection('/tmp/.X11-unix/X' + displayNum);