diff --git a/tests/unit/bundle_test.py b/tests/unit/bundle_test.py
index 8faebb7f1f..e4f07d6e48 100644
--- a/tests/unit/bundle_test.py
+++ b/tests/unit/bundle_test.py
@@ -91,7 +91,8 @@ def test_to_bundle():
         volumes={'special': {}},
         networks={'extra': {}},
         secrets={},
-        configs={}
+        configs={},
+        project_name=''
     )
 
     with mock.patch('compose.bundle.log.warning', autospec=True) as mock_log: