diff --git a/test/unit/tool_shed/_util.py b/test/unit/tool_shed/_util.py
index d59991bca0f1..cf4f82255d0c 100644
--- a/test/unit/tool_shed/_util.py
+++ b/test/unit/tool_shed/_util.py
@@ -46,6 +46,7 @@ class TestToolShedConfig:
     file_path: str
     id_secret: str = "thisistheshedunittestsecret"
     smtp_server: Optional[str] = None
+    hgweb_repo_prefix = "repos/"
     config_hg_for_dev = False
 
     def __init__(self, temp_directory):