diff --git a/firefox/40-no_proxy.yml b/firefox/40-no_proxy.yml
index 0937690b..55a57242 100644
--- a/firefox/40-no_proxy.yml
+++ b/firefox/40-no_proxy.yml
@@ -4,6 +4,7 @@ version: 1.1
 
 no_proxy:
   description: Address for which proxy will be desactivated
+  help: Connections to localhost, 127.0.0.1/8 and ::1 are never proxied
   examples:
     - .mozilla.org
     - .net.nz