diff --git a/firefox/10-manual.yml b/firefox/10-manual.yml
index 100695b..3bc1f58 100644
--- a/firefox/10-manual.yml
+++ b/firefox/10-manual.yml
@@ -3,7 +3,7 @@ manual:
   description: Manual proxy configuration
   type: family
   disabled:
-    variable: proxy_mode
+    variable: _.proxy_mode
     when_not: 'Manual proxy configuration'
 
   http_proxy: