diff --git a/lib/plugins/styling/script.js b/lib/plugins/styling/script.js
index 074c8dc402..3859190c77 100644
--- a/lib/plugins/styling/script.js
+++ b/lib/plugins/styling/script.js
@@ -78,8 +78,8 @@ jQuery(function () {
     // reload the main page on close
     window.onunload = function(e) {
         if(doreload) {
-            window.opener.DokuCookie.setValue('styling_plugin', 0);
-            window.opener.document.location.reload();
+            DokuCookie.setValue('styling_plugin', 0);
+            if(window.opener) window.opener.document.location.reload();
         }
         return null;
     };
@@ -90,8 +90,8 @@ jQuery(function () {
     });
 
     // on first load apply preview
-    applyPreview(window.opener);
+    if(window.opener) applyPreview(window.opener);
 
     // enable the preview cookie
-    window.opener.DokuCookie.setValue('styling_plugin', 1);
+    DokuCookie.setValue('styling_plugin', 1);
 });