diff --git a/swh/indexer/tests/conftest.py b/swh/indexer/tests/conftest.py
--- a/swh/indexer/tests/conftest.py
+++ b/swh/indexer/tests/conftest.py
@@ -116,10 +116,9 @@
 
     """
     objstorage = get_objstorage(**swh_indexer_config["objstorage"])
+    print("mocked %r" % objstorage)
     fill_obj_storage(objstorage)
-    with patch.dict(
-        "swh.objstorage.factory._STORAGE_CLASSES", {"memory": lambda: objstorage}
-    ):
+    with patch("swh.indexer.indexer.get_objstorage", return_value=objstorage):
         yield objstorage