diff --git a/Rougail/socle/03-proxy.yml b/Rougail/socle/03-proxy.yml
index 41e290c..da353a1 100644
--- a/Rougail/socle/03-proxy.yml
+++ b/Rougail/socle/03-proxy.yml
@@ -16,3 +16,8 @@ env_proxy:
     type: domainname
     test:
       - proxy.silique.fr
+  port:
+    description: The proxy server's port
+    type: port
+    test:
+      - "3128"