diff --git a/swh/indexer/storage/api/server.py b/swh/indexer/storage/api/server.py
--- a/swh/indexer/storage/api/server.py
+++ b/swh/indexer/storage/api/server.py
@@ -92,8 +92,7 @@
                 "'local' configuration"
             )
 
-        args = vcfg["args"]
-        if not args.get("db"):
+        if not vcfg.get("db"):
             raise ValueError("Invalid configuration; missing 'db' config entry")
 
     return cfg
diff --git a/swh/indexer/tests/storage/test_server.py b/swh/indexer/tests/storage/test_server.py
--- a/swh/indexer/tests/storage/test_server.py
+++ b/swh/indexer/tests/storage/test_server.py
@@ -33,12 +33,13 @@
 
 @pytest.mark.parametrize("config_path", [None, ""])
 def test_load_and_check_config_no_configuration(config_path) -> None:
-    """Inexistent configuration files raises"""
+    """Irrelevant configuration file path raises"""
     with pytest.raises(EnvironmentError, match="Configuration file must be defined"):
         load_and_check_config(config_path)
 
 
 def test_load_and_check_inexistent_config_path() -> None:
+    """Inexistent configuration file raises"""
     config_path = "/indexer/inexistent/config.yml"
     expected_error = f"Configuration file {config_path} does not exist"
     with pytest.raises(FileNotFoundError, match=expected_error):
@@ -52,22 +53,37 @@
         load_and_check_config(config_path)
 
 
-def test_load_and_check_config_remote_config_local_type_raise(tmpdir) -> None:
-    """'local' configuration without 'local' storage raises"""
-    config = {"indexer_storage": {"cls": "remote", "args": {}}}
-    config_path = prepare_config_file(tmpdir, config)
+@pytest.mark.parametrize("class_storage", ["remote", "memory"])
+def test_load_and_check_config_remote_config_local_type_raise(
+    class_storage, tmpdir
+) -> None:
+    """Any other configuration than 'local' (the default) is rejected"""
+    assert class_storage != "local"
+    incompatible_config = {"indexer_storage": {"cls": class_storage}}
+    config_path = prepare_config_file(tmpdir, incompatible_config)
 
     expected_error = (
         "The indexer_storage backend can only be started with a 'local' "
         "configuration"
     )
+    with pytest.raises(ValueError, match=expected_error):
+        load_and_check_config(config_path)
     with pytest.raises(ValueError, match=expected_error):
         load_and_check_config(config_path, type="local")
 
 
+def test_load_and_check_config_remote_config_fine(tmpdir) -> None:
+    """'Remote configuration is fine (when changing the default type)"""
+    config = {"indexer_storage": {"cls": "remote"}}
+    config_path = prepare_config_file(tmpdir, config)
+    cfg = load_and_check_config(config_path, type="any")
+
+    assert cfg == config
+
+
 def test_load_and_check_config_local_incomplete_configuration(tmpdir) -> None:
     """Incomplete 'local' configuration should raise"""
-    config = {"indexer_storage": {"cls": "local", "args": {}}}
+    config = {"indexer_storage": {"cls": "local"}}
 
     expected_error = "Invalid configuration; missing 'db' config entry"
     config_path = prepare_config_file(tmpdir, config)
@@ -76,17 +92,8 @@
 
 
 def test_load_and_check_config_local_config_fine(tmpdir) -> None:
-    """'Remote configuration is fine"""
-    config = {"indexer_storage": {"cls": "local", "args": {"db": "db",}}}
+    """'Complete 'local' configuration is fine"""
+    config = {"indexer_storage": {"cls": "local", "db": "db",}}
     config_path = prepare_config_file(tmpdir, config)
     cfg = load_and_check_config(config_path, type="local")
     assert cfg == config
-
-
-def test_load_and_check_config_remote_config_fine(tmpdir) -> None:
-    """'Remote configuration is fine"""
-    config = {"indexer_storage": {"cls": "remote", "args": {}}}
-    config_path = prepare_config_file(tmpdir, config)
-    cfg = load_and_check_config(config_path, type="any")
-
-    assert cfg == config