diff --git a/tests/test_tutorial/test_custom_docs_ui/test_tutorial001.py b/tests/test_tutorial/test_custom_docs_ui/test_tutorial001.py
index 6033adc64f..f4fe9f9f4a 100644
--- a/tests/test_tutorial/test_custom_docs_ui/test_tutorial001.py
+++ b/tests/test_tutorial/test_custom_docs_ui/test_tutorial001.py
@@ -39,6 +39,7 @@ def test_swagger_ui_html(client: TestClient, path_prefix: str):
     assert f"{path_prefix}/docs/oauth2-redirect" in response.text
 
 
+@workdir_lock
 def test_openapi_json(client: TestClient, path_prefix: str):
     response = client.get(f"{path_prefix}/openapi.json")
     assert response.request.url == f"http://server{path_prefix}/openapi.json"