diff --git a/swh/objstorage/tests/test_server.py b/swh/objstorage/tests/test_server.py
index 165b658..179864d 100644
--- a/swh/objstorage/tests/test_server.py
+++ b/swh/objstorage/tests/test_server.py
@@ -1,116 +1,115 @@
 # Copyright (C) 2019  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
 
 import copy
 
 import pytest
 import yaml
 
 from swh.objstorage.api.server import load_and_check_config
 
 
 def prepare_config_file(tmpdir, content, name="config.yml"):
     """Prepare configuration file in `$tmpdir/name` with content `content`.
 
     Args:
         tmpdir (LocalPath): root directory
         content (str/dict): Content of the file either as string or as a dict.
                             If a dict, converts the dict into a yaml string.
         name (str): configuration filename
 
     Returns
         path (str) of the configuration file prepared.
 
     """
     config_path = tmpdir / name
     if isinstance(content, dict):  # convert if needed
         content = yaml.dump(content)
     config_path.write_text(content, encoding="utf-8")
     # pytest on python3.5 does not support LocalPath manipulation, so
     # convert path to string
     return str(config_path)
 
 
 def test_load_and_check_config_no_configuration():
     """Inexistent configuration files raises"""
     with pytest.raises(EnvironmentError, match="Configuration file must be defined"):
         load_and_check_config(None)
 
     config_path = "/indexer/inexistent/config.yml"
     with pytest.raises(FileNotFoundError, match=f"{config_path} does not exist"):
         load_and_check_config(config_path)
 
 
 def test_load_and_check_config_invalid_configuration_toplevel(tmpdir):
     """Invalid configuration raises"""
     config = {"something": "useless"}
     config_path = prepare_config_file(tmpdir, content=config)
     with pytest.raises(KeyError, match="missing objstorage config entry"):
         load_and_check_config(config_path)
 
 
 def test_load_and_check_config_invalid_configuration(tmpdir):
     """Invalid configuration raises"""
     config_path = prepare_config_file(
         tmpdir, content={"objstorage": {"something": "useless"}}
     )
     with pytest.raises(KeyError, match="missing cls config entry"):
         load_and_check_config(config_path)
 
 
 def test_load_and_check_config_invalid_configuration_level2(tmpdir):
     """Invalid configuration at 2nd level raises"""
     config = {
         "objstorage": {
             "cls": "pathslicing",
             "args": {"root": "root", "slicing": "slicing",},
             "client_max_size": "10",
         }
     }
     for key in ("root", "slicing"):
         c = copy.deepcopy(config)
         c["objstorage"]["args"].pop(key)
         config_path = prepare_config_file(tmpdir, c)
         with pytest.raises(KeyError, match=f"missing {key} config entry"):
             load_and_check_config(config_path)
 
 
-def test_load_and_check_config_fine(tmpdir):
+@pytest.mark.parametrize(
+    "config",
+    [
+        pytest.param(
+            {
+                "objstorage": {
+                    "cls": "pathslicing",
+                    "args": {"root": "root", "slicing": "slicing"},
+                }
+            },
+            id="pathslicing-bw-compat",
+        ),
+        pytest.param(
+            {
+                "objstorage": {
+                    "cls": "pathslicing",
+                    "root": "root",
+                    "slicing": "slicing",
+                }
+            },
+            id="pathslicing",
+        ),
+        pytest.param(
+            {"client_max_size": "10", "objstorage": {"cls": "memory", "args": {}}},
+            id="empty-args-bw-compat",
+        ),
+        pytest.param(
+            {"client_max_size": "10", "objstorage": {"cls": "memory"}}, id="empty-args"
+        ),
+    ],
+)
+def test_load_and_check_config(tmpdir, config):
     """pathslicing configuration fine loads ok"""
-    config = {
-        "objstorage": {
-            "cls": "pathslicing",
-            "args": {"root": "root", "slicing": "slicing",},
-        }
-    }
-
-    config_path = prepare_config_file(tmpdir, config)
-    cfg = load_and_check_config(config_path)
-    assert cfg == config
-
-
-def test_load_and_check_config_no_args(tmpdir):
-    """pathslicing configuration with no args key loads ok"""
-    config = {
-        "objstorage": {"cls": "pathslicing", "root": "root", "slicing": "slicing"}
-    }
-
-    config_path = prepare_config_file(tmpdir, config)
-    cfg = load_and_check_config(config_path)
-    assert cfg == config
-
-
-def test_load_and_check_config_fine2(tmpdir):
-    config = {"client_max_size": "10", "objstorage": {"cls": "memory", "args": {}}}
-    config_path = prepare_config_file(tmpdir, config)
-    cfg = load_and_check_config(config_path)
-    assert cfg == config
-
-
-def test_load_and_check_config_only_cls(tmpdir):
-    config = {"client_max_size": "10", "objstorage": {"cls": "memory"}}
     config_path = prepare_config_file(tmpdir, config)
     cfg = load_and_check_config(config_path)
     assert cfg == config