diff --git a/src/bg/is-enabled.js b/src/bg/is-enabled.js
index ca78c38a5..b96914112 100644
--- a/src/bg/is-enabled.js
+++ b/src/bg/is-enabled.js
@@ -9,6 +9,7 @@ of Greasemonkey.
 let isEnabled = true;
 chrome.storage.local.get('globalEnabled', v => {
   isEnabled = v['globalEnabled'];
+  if ('undefined' == typeof isEnabled) isEnabled = true;
   setIcon();
 });