diff --git a/basic/portal-app-manager.py b/basic/portal-app-manager.py
index b496220..3e333f5 100755
--- a/basic/portal-app-manager.py
+++ b/basic/portal-app-manager.py
@@ -20,11 +20,10 @@ def main(args):
     with open(jsonfile, 'w') as f:
         json.dump(data, f)
 
-
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(description='Spotter Cluster portal application manager')
     parser.add_argument('app', help='Application ID.')
-    parser.add_argument('url', default=None, help='URL to the application. Use "{host}" as a host placeholder.')
-    parser.add_argument('login', default=None, help='Administrative login.')
-    parser.add_argument('password', default=None, help='Administrative password.')
+    parser.add_argument('url', nargs='?', help='URL to the application. Use "{host}" as a host placeholder.')
+    parser.add_argument('login', nargs='?', help='Administrative login.')
+    parser.add_argument('password', nargs='?', help='Administrative password.')
     main(parser.parse_args())