diff --git a/cloudron.js b/cloudron.js
index c653c39..6d74460 100644
--- a/cloudron.js
+++ b/cloudron.js
@@ -41,7 +41,12 @@ Cloudron.prototype.getOauthToken = function (user) {
     var sessionCookies = res.headers['set-cookie']; // always an array
 
     ///////// should get redirected to login form with a script tag (to workaround chrome issue with redirects+cookies)
-    var urlp = url.parse(res.text.match(/window.location.href = "(.*)"/)[1]);
+    var redirectUrl = res.text.match(/window.location.href = "(.*)"/);
+    if (!redirectUrl) {
+        debug('Could not determine redirected url', res.text);
+        assert(false);
+    }
+    var urlp = url.parse(redirectUrl[1]);
 
     ////////// get the login form (api/v1/session/login)
     res = request.get(this._origin + urlp.pathname).set('cookie', sessionCookies[0]).query(urlp.query).end();