diff --git a/storage/api/compose_objects.py b/storage/api/compose_objects.py
index 18fe5058fa3..5fae149445b 100644
--- a/storage/api/compose_objects.py
+++ b/storage/api/compose_objects.py
@@ -99,5 +99,5 @@ def main(bucket, destination, sources):
 
     args = parser.parse_args()
 
-    main(parser.bucket, parser.destination, parser.sources)
+    main(args.bucket, args.destination, args.sources)
 # [END all]