diff --git a/4chan_x.user.js b/4chan_x.user.js
index 89fe9fbf3..775081f63 100644
--- a/4chan_x.user.js
+++ b/4chan_x.user.js
@@ -1899,7 +1899,7 @@
     message: {
       send: function(data) {
         var host, window;
-        if (engine === 'webkit') {
+        if (/chrome/i.test(navigator.userAgent)) {
           qr.message.receive(data);
           return;
         }
diff --git a/script.coffee b/script.coffee
index 57b15dd6d..233be78fc 100644
--- a/script.coffee
+++ b/script.coffee
@@ -1469,7 +1469,8 @@ qr =
 
   message:
     send: (data) ->
-      if engine is 'webkit'
+      # CORS is ignored for content script on Chrome, but not Safari/Oprah/Firefox.
+      if /chrome/i.test navigator.userAgent
         qr.message.receive data
         return
       data.qr = true