diff --git a/static/js/init.js b/static/js/init.js
index 4c48650..343f899 100644
--- a/static/js/init.js
+++ b/static/js/init.js
@@ -1,3 +1,5 @@
+/* global M */
+
 var options = {};
 var elem = document.querySelector(".sidenav");
 var instance = M.Sidenav.init(elem, options);