diff --git a/lib/utils.js b/lib/utils.js
index c7ff1bf2..a0131ec5 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -156,6 +156,10 @@ utils.createXHR = function(method, url, payload, callback) {
             delete xhrDefaultHeaders[k];
         }
     }
+    if ('withCredentials' in xhr) {
+        // Set cookies on CORS, please.
+        xhr.withCredentials = "true";
+    }
 
     var cleanup = function() {
         // IE needs this field to be a function