diff --git a/chrome/content/zotero/xpcom/cookieSandbox.js b/chrome/content/zotero/xpcom/cookieSandbox.js
index 7b974e9304..6848681a9b 100755
--- a/chrome/content/zotero/xpcom/cookieSandbox.js
+++ b/chrome/content/zotero/xpcom/cookieSandbox.js
@@ -336,8 +336,7 @@ Zotero.CookieSandbox.Observer = new function() {
 			} else {
 				// try the browser
 				try {
-					browser = notificationCallbacks.getInterface(Ci.nsIWebNavigation)
-						.QueryInterface(Ci.nsIDocShell).chromeEventHandler;
+					browser = notificationCallbacks.getInterface(Ci.nsILoadContext).topFrameElement;
 				} catch(e) {}
 				if(browser) {
 					tested = true;