diff --git a/4chan_x.user.js b/4chan_x.user.js
index 9a8cde8b1..87377ccf5 100644
--- a/4chan_x.user.js
+++ b/4chan_x.user.js
@@ -730,7 +730,9 @@
         if (((_ref = e.target.nodeName) === 'TEXTAREA' || _ref === 'INPUT') && !e.altKey && !e.ctrlKey && !(e.keyCode === 27)) {
           return;
         }
-        key = keybinds.cb.keyCode(e);
+        if (!(key = keybinds.cb.keyCode(e))) {
+          return;
+        }
         thread = nav.getThread();
         switch (key) {
           case conf.close:
@@ -1126,7 +1128,9 @@
     keybind: function(e) {
       e.preventDefault();
       e.stopPropagation();
-      key = keybinds.cb.keyCode(e);
+      if (!(key = keybinds.cb.keyCode(e))) {
+        return;
+      }
       this.value = key;
       $.setValue(this.name, key);
       return conf[this.name] = key;
diff --git a/script.coffee b/script.coffee
index d5b6edfd5..60782e9c9 100644
--- a/script.coffee
+++ b/script.coffee
@@ -520,7 +520,7 @@ keybinds =
   cb:
     keydown: (e) ->
       return if e.target.nodeName in ['TEXTAREA', 'INPUT'] and not e.altKey and not e.ctrlKey and not (e.keyCode is 27)
-      key = keybinds.cb.keyCode e
+      return unless key = keybinds.cb.keyCode e
 
       thread = nav.getThread()
       switch key
@@ -891,7 +891,7 @@ options =
   keybind: (e) ->
     e.preventDefault()
     e.stopPropagation()
-    key = keybinds.cb.keyCode e
+    return unless key = keybinds.cb.keyCode e
     @value = key
     $.setValue @name, key
     conf[@name] = key