diff --git a/gef.py b/gef.py
index 38bfa1951..b2e02dfee 100644
--- a/gef.py
+++ b/gef.py
@@ -493,7 +493,7 @@ def wrapper(*args: Any, **kwargs: Any) -> Callable:
                     continue
                 elif argtype in (list, tuple):
                     parser.add_argument(*argname, type=type(argvalue[0]),
-                                        default=[], action='append')
+                                        default=[], action="append")
                     continue
                 parser.add_argument(*argname, type=argtype, default=argvalue)