diff --git a/firefox/20-manual.yml b/firefox/20-manual.yml
index f7295f0b..3e15a0b9 100644
--- a/firefox/20-manual.yml
+++ b/firefox/20-manual.yml
@@ -16,9 +16,12 @@ manual:
       type: domainname
       params:
         allow_ip: true
+      default:
+        variable: __.http_proxy.address
 
     port:
       description: HTTPS Port
       type: port
-      default: 8080
+      default:
+        variable: __.http_proxy.port
 ...