diff --git a/src/jcloud_docsgen/cli.py b/src/jcloud_docsgen/cli.py
index b153c0a..0c0596e 100644
--- a/src/jcloud_docsgen/cli.py
+++ b/src/jcloud_docsgen/cli.py
@@ -33,6 +33,6 @@ def existing_directory(path: str) -> pathlib.Path:
 
 def main() -> int:
     argument_parser = argparse.ArgumentParser()
-    argument_parser.add_argument('project_directory', type = existing_directory, default = pathlib.Path('.'), help = 'The directory of the project')
+    argument_parser.add_argument('project_directory', type = existing_directory, nargs = '?', default = pathlib.Path('.'), help = 'The directory of the project')
     args = argument_parser.parse_args()
     return 0