diff --git a/swh/indexer/tests/conftest.py b/swh/indexer/tests/conftest.py
index e60b77c..3501188 100644
--- a/swh/indexer/tests/conftest.py
+++ b/swh/indexer/tests/conftest.py
@@ -1,81 +1,81 @@
 # Copyright (C) 2019-2020  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 from datetime import timedelta
 from unittest.mock import patch
 
 import pytest
 
 from swh.objstorage import get_objstorage
 from swh.scheduler.tests.conftest import *  # noqa
 from swh.storage import get_storage
 from swh.indexer.storage import get_indexer_storage
 
 from .utils import fill_storage, fill_obj_storage
 
 
 TASK_NAMES = ['revision_intrinsic_metadata', 'origin_intrinsic_metadata']
 
 
 @pytest.fixture
 def indexer_scheduler(swh_scheduler):
     for taskname in TASK_NAMES:
         swh_scheduler.create_task_type({
             'type': taskname,
             'description': 'The {} indexer testing task'.format(taskname),
             'backend_name': 'swh.indexer.tests.tasks.{}'.format(taskname),
             'default_interval': timedelta(days=1),
             'min_interval': timedelta(hours=6),
             'max_interval': timedelta(days=12),
             'num_retries': 3,
         })
     return swh_scheduler
 
 
 @pytest.fixture
 def idx_storage():
     """An instance of in-memory indexer storage that gets injected into all
     indexers classes.
 
     """
     idx_storage = get_indexer_storage('memory', {})
-    with patch('swh.indexer.storage.get_indexer_storage') \
+    with patch('swh.indexer.storage.in_memory.IndexerStorage') \
             as idx_storage_mock:
         idx_storage_mock.return_value = idx_storage
         yield idx_storage
 
 
 @pytest.fixture
 def storage():
     """An instance of in-memory storage that gets injected into all indexers
        classes.
 
     """
     storage = get_storage('memory')
     fill_storage(storage)
-    with patch('swh.storage.get_storage') as storage_mock:
+    with patch('swh.storage.in_memory.InMemoryStorage') as storage_mock:
         storage_mock.return_value = storage
         yield storage
 
 
 @pytest.fixture
 def obj_storage():
     """An instance of in-memory objstorage that gets injected into all indexers
     classes.
 
     """
     objstorage = get_objstorage('memory', {})
     fill_obj_storage(objstorage)
-    with patch('swh.objstorage.get_objstorage') as objstorage_mock:
-        objstorage_mock.return_value = objstorage
+    with patch.dict('swh.objstorage._STORAGE_CLASSES',
+                    {'memory': lambda: objstorage}):
         yield objstorage
 
 
 @pytest.fixture(scope='session')  # type: ignore  # expected redefinition
 def celery_includes():
     return [
         'swh.indexer.tests.tasks',
         'swh.indexer.tasks',
     ]