diff --git a/fastapi/dependencies/utils.py b/fastapi/dependencies/utils.py
index a09f08291..a4f9df95a 100644
--- a/fastapi/dependencies/utils.py
+++ b/fastapi/dependencies/utils.py
@@ -131,7 +131,7 @@ def get_parameterless_sub_dependant(*, depends: params.Depends, path: str) -> De
     )
     use_security_scopes: List[str] = []
     if isinstance(depends, params.Security) and depends.scopes:
-        use_security_scopes = use_security_scopes + list(depends.scopes)
+        use_security_scopes.extend(depends.scopes)
     return get_dependant(
         path=path, call=depends.dependency, security_scopes=use_security_scopes
     )