diff --git a/src/rougail/tiramisu.py b/src/rougail/tiramisu.py
index 461b58402..db43ad524 100644
--- a/src/rougail/tiramisu.py
+++ b/src/rougail/tiramisu.py
@@ -125,7 +125,7 @@ CONVERT_OPTION = {
         example="https://example.net",
     ),
     "port": dict(
-        opttype="PortOption", initkwargs={"allow_private": True}, example="111"
+        opttype="PortOption", initkwargs={"allow_private": True}, example="111", func=str,
     ),
     "mac": dict(opttype="MACOption", example="00:00:00:00:00"),
     "unix_permissions": dict(
@@ -392,14 +392,16 @@ def jinja_to_property_help(prop, description, **kwargs):
 
 
 @function_waiting_for_error
-def valid_with_jinja(warnings_only=False, **kwargs):
+def valid_with_jinja(warnings_only=False, description=None, **kwargs):
     global ValueWarning
     value = func["jinja_to_function"](**kwargs)
     if value:
+        if description is None:
+            description = value
         if warnings_only:
-            raise ValueWarning(value)
+            raise ValueWarning(description)
         else:
-            raise ValueError(value)
+            raise ValueError(description)
 
 
 func["calc_value"] = rougail_calc_value