diff --git a/swh/vault/tests/conftest.py b/swh/vault/tests/conftest.py
--- a/swh/vault/tests/conftest.py
+++ b/swh/vault/tests/conftest.py
@@ -52,14 +52,12 @@
         'db': db_url('tests', postgresql_proc),
         'storage': {
             'cls': 'local',
-            'args': {
-                'db': db_url('tests2', postgresql_proc),
-                'objstorage': {
-                    'cls': 'pathslicing',
-                    'args': {
-                        'root': str(tmp_path),
-                        'slicing': '0:1/1:5',
-                    },
+            'db': db_url('tests2', postgresql_proc),
+            'objstorage': {
+                'cls': 'pathslicing',
+                'args': {
+                    'root': str(tmp_path),
+                    'slicing': '0:1/1:5',
                 },
             },
         },
diff --git a/swh/vault/tests/test_cookers.py b/swh/vault/tests/test_cookers.py
--- a/swh/vault/tests/test_cookers.py
+++ b/swh/vault/tests/test_cookers.py
@@ -481,13 +481,11 @@
             dir_id_hex = repo.repo[c].tree.decode()
             dir_id = hashutil.hash_to_bytes(dir_id_hex)
 
-        test_id = b'56789012345678901234'
         test_revision = Revision.from_dict({
-            'id': test_id,
-            'message': None,
-            'author': {'name': None, 'email': None, 'fullname': ''},
+            'message': b'',
+            'author': {'name': None, 'email': None, 'fullname': b''},
             'date': None,
-            'committer': {'name': None, 'email': None, 'fullname': ''},
+            'committer': {'name': None, 'email': None, 'fullname': b''},
             'committer_date': None,
             'parents': [],
             'type': 'git',
@@ -498,17 +496,15 @@
 
         swh_storage.revision_add([test_revision])
 
-        with cook_extract_revision_gitfast(swh_storage, test_id) as (ert, p):
+        with cook_extract_revision_gitfast(swh_storage,
+                                           test_revision.id) as (ert, p):
             ert.checkout(b'HEAD')
             assert (p / 'file').stat().st_mode == 0o100644
 
     def test_revision_revision_data(self, swh_storage):
         target_rev = '0e8a3ad980ec179856012b7eecf4327e99cd44cd'
-        d = hashutil.hash_to_bytes('17a3e48bce37be5226490e750202ad3a9a1a3fe9')
-        r = hashutil.hash_to_bytes('1ecc9270c4fc61cfddbc65a774e91ef5c425a6f0')
 
         dir = Directory.from_dict({
-            'id': d,
             'entries': [
                 {
                     'name': b'submodule',
@@ -521,20 +517,19 @@
         swh_storage.directory_add([dir])
 
         rev = Revision.from_dict({
-            'id': r,
-            'message': None,
-            'author': {'name': None, 'email': None, 'fullname': ''},
+            'message': b'',
+            'author': {'name': None, 'email': None, 'fullname': b''},
             'date': None,
-            'committer': {'name': None, 'email': None, 'fullname': ''},
+            'committer': {'name': None, 'email': None, 'fullname': b''},
             'committer_date': None,
             'parents': [],
             'type': 'git',
-            'directory': d,
+            'directory': dir.id,
             'metadata': {},
             'synthetic': True
         })
         swh_storage.revision_add([rev])
 
-        with cook_stream_revision_gitfast(swh_storage, r) as stream:
+        with cook_stream_revision_gitfast(swh_storage, rev.id) as stream:
             pattern = 'M 160000 {} submodule'.format(target_rev).encode()
             assert pattern in stream.read()