diff --git a/dlibrary/dlibrary.py b/dlibrary/dlibrary.py
index 261c3fa..eec8ea4 100755
--- a/dlibrary/dlibrary.py
+++ b/dlibrary/dlibrary.py
@@ -358,7 +358,7 @@ argparser.add_argument(
     default=Path('./dlibrary'),
     help='directory to store dlibrary content and metadata to (default: ./dlibrary)',
 )
-subparsers = argparser.add_subparsers(title="subcommands")
+subparsers = argparser.add_subparsers(title="subcommands", required=True)
 
 parser_extract = subparsers.add_parser('extract', help='extract zipfiles')
 parser_extract.add_argument(