diff --git a/node_modules/c9/blacklist.js b/node_modules/c9/blacklist.js
index 5479d6ea..85cfb617 100644
--- a/node_modules/c9/blacklist.js
+++ b/node_modules/c9/blacklist.js
@@ -4,6 +4,8 @@ var _ = require("lodash");
 var internalDomain = ['c9.io', 'clou9beta.com'];
 
 function hasInternalDomain(email) {
+    if (!email) return false;
+    
     var emailElements = email.split("@");
     var emailDomain = emailElements[emailElements.length - 1];