diff --git a/python/scripts/mkvenv.py b/python/scripts/mkvenv.py
index 558619910e..8c036c019a 100644
--- a/python/scripts/mkvenv.py
+++ b/python/scripts/mkvenv.py
@@ -854,6 +854,7 @@ def main() -> int:
     subparsers = parser.add_subparsers(
         title="Commands",
         dest="command",
+        required=True,
         metavar="command",
         help="Description",
     )