diff --git a/src/ytdl_sub/script/script.py b/src/ytdl_sub/script/script.py
index 699e5eb9..f285eae6 100644
--- a/src/ytdl_sub/script/script.py
+++ b/src/ytdl_sub/script/script.py
@@ -477,7 +477,7 @@ class Script:
                     added_variables_to_validate.add(name)
 
                 if name in functions_to_add:
-                    self._functions[_function_name(name)] = parsed
+                    self._functions[name] = parsed
                 else:
                     self._variables[name] = parsed
 
diff --git a/tests/unit/script/test_script.py b/tests/unit/script/test_script.py
index f313c511..dfa7994e 100644
--- a/tests/unit/script/test_script.py
+++ b/tests/unit/script/test_script.py
@@ -80,4 +80,8 @@ class TestScript:
             }
         )
 
-        assert script.resolve_once({"url": "{ %bilateral_url('nope') }"})["url"].native == "nope"
+        script.add({"%bilateral_url_wrap": "{ %bilateral_url($0) }"})
+
+        assert (
+            script.resolve_once({"url": "{ %bilateral_url_wrap('nope') }"})["url"].native == "nope"
+        )