diff --git a/app/assets/javascripts/application.js.coffee b/app/assets/javascripts/application.js.coffee
index 20dc4425b4..b1504c06e2 100644
--- a/app/assets/javascripts/application.js.coffee
+++ b/app/assets/javascripts/application.js.coffee
@@ -255,7 +255,7 @@ $ ->
   new Aside()
 
   # Sidenav pinning
-  if $window.width() < 1280 and $.cookie('pin_nav') is 'true'
+  if $(window).width() < 1280 and $.cookie('pin_nav') is 'true'
     $.cookie('pin_nav', 'false', { path: '/' })
     $('.page-with-sidebar')
       .toggleClass('page-sidebar-collapsed page-sidebar-expanded')