diff --git a/packages/xo-lib/api.js b/packages/xo-lib/api.js
index 501883920..d333e6aed 100644
--- a/packages/xo-lib/api.js
+++ b/packages/xo-lib/api.js
@@ -18,7 +18,7 @@ var fixUrl = require('./fix-url')
 function getCurrentUrl () {
   /* global window: false */
 
-  if (typeof window === undefined) {
+  if (typeof window === 'undefined') {
     throw new Error('cannot get current URL')
   }