diff --git a/firefox/10-manual.yml b/firefox/10-manual.yml
index 1b3761b4..40a493dc 100644
--- a/firefox/10-manual.yml
+++ b/firefox/10-manual.yml
@@ -11,4 +11,10 @@ manual:
   http_proxy:
     description: HTTP Proxy
     type: proxy
+
+    address:
+      default: null
+
+    port:
+      default: 8080
 ...
diff --git a/types/proxy/00-type.yml b/types/proxy/00-type.yml
index d5db5867..6877fb89 100644
--- a/types/proxy/00-type.yml
+++ b/types/proxy/00-type.yml
@@ -9,9 +9,12 @@ proxy:
     type: domainname
     params:
       allow_ip: true
+    default:
+      variable: __.http_proxy.address
 
   port:
     description: Proxy port
     type: port
-    default: 8080
+    default:
+      variable: __.http_proxy.port
 ...