diff --git a/swh/core/config.py b/swh/core/config.py
--- a/swh/core/config.py
+++ b/swh/core/config.py
@@ -287,68 +287,37 @@
 
 
 class SWHConfig:
-    """Mixin to add configuration parsing abilities to classes
+    """Mixin to add configuration parsing abilities to classes.
 
-    The class should override the class attributes:
-        - DEFAULT_CONFIG (default configuration to be parsed)
-        - CONFIG_BASE_FILENAME (the filename of the configuration to be used)
+    The class should override the class attribute DEFAULT_CONFIG to provide default
+    key/value entries which need to be set if not defined in the configuration file.
 
-    This class defines one classmethod, parse_config_file, which
-    parses a configuration file using the default config as set in the
-    class attribute.
+    This class defines one classmethod, func:`parse_config_file`, which parses a
+    configuration file, provided through the SWH_CONFIG_FILENAME environment variable.
+    Eventually enriched with default configuration as per the class attribute
+    DEFAULT_CONFIG.
 
     """
 
-    DEFAULT_CONFIG = {}  # type: Dict[str, Tuple[str, Any]]
-    CONFIG_BASE_FILENAME = ""  # type: Optional[str]
+    DEFAULT_CONFIG: Dict[str, Any] = {}
 
     @classmethod
-    def parse_config_file(
-        cls,
-        base_filename=None,
-        config_filename=None,
-        additional_configs=None,
-        global_config=True,
-    ):
+    def parse_config_file(cls):
         """Parse the configuration file associated to the current class.
 
-        By default, parse_config_file will load the configuration
-        cls.CONFIG_BASE_FILENAME from one of the Software Heritage
-        configuration directories, in order, unless it is overridden
-        by base_filename or config_filename (which shortcuts the file
-        lookup completely).
-
-        Args:
-            - base_filename (str): overrides the default
-              cls.CONFIG_BASE_FILENAME
-            - config_filename (str): sets the file to parse instead of
-              the defaults set from cls.CONFIG_BASE_FILENAME
-            - additional_configs: (list of default configuration dicts)
-              allows to override or extend the configuration set in
-              cls.DEFAULT_CONFIG.
-            - global_config (bool): Load the global configuration (default:
-              True)
-        """
-
-        if config_filename:
-            config_filenames = [config_filename]
-        elif "SWH_CONFIG_FILENAME" in os.environ:
-            config_filenames = [os.environ["SWH_CONFIG_FILENAME"]]
-        else:
-            if not base_filename:
-                base_filename = cls.CONFIG_BASE_FILENAME
-            config_filenames = swh_config_paths(base_filename)
-        if not additional_configs:
-            additional_configs = []
+        By default, func:`parse_config_file` will load the configuration from the file
+        referenced by the environment variable SWH_CONFIG_FILENAME. If not set, this
+        will raise a ValueError requesting the environment variable to be set.
 
-        full_default_config = merge_default_configs(
-            cls.DEFAULT_CONFIG, *additional_configs
-        )
+        Raises:"
+            ValueError if SWH_CONFIG_FILENAME is undefined
 
-        config = {}
-        if global_config:
-            config = load_global_config()
+        """
 
-        config.update(priority_read(config_filenames, full_default_config))
+        if "SWH_CONFIG_FILENAME" not in os.environ:
+            raise ValueError("SWH_CONFIG_FILENAME environment variable is undefined.")
 
-        return config
+        cfg_path = os.environ["SWH_CONFIG_FILENAME"]
+        cfg = read_raw_config(config_basepath(cfg_path))
+        cfg = merge_configs(cls.DEFAULT_CONFIG, cfg)
+        return cfg
diff --git a/swh/core/tests/test_config.py b/swh/core/tests/test_config.py
--- a/swh/core/tests/test_config.py
+++ b/swh/core/tests/test_config.py
@@ -326,3 +326,44 @@
             config.merge_configs({"a": v}, {"a": {}})
         with pytest.raises(TypeError):
             config.merge_configs({"a": {}}, {"a": v})
+
+
+def test_swhconfig_mixin_no_swh_config_filename():
+    """Without SWH_CONFIG_FILENAME set, SWHConfig.parse_config_file raises"""
+
+    with pytest.raises(ValueError, match="SWH_CONFIG_FILENAME environment"):
+        config.SWHConfig.parse_config_file()
+
+
+def test_swhconfig_mixin_no_default(swh_config, monkeypatch):
+    config_path = str(swh_config)
+    monkeypatch.setenv("SWH_CONFIG_FILENAME", config_path)
+
+    actual_config = config.SWHConfig.parse_config_file()
+
+    expected_config = config.read(config_path)
+    assert actual_config == expected_config
+
+
+def test_swhconfig_mixin_with_inheritance(swh_config, monkeypatch):
+    class TestConfig(config.SWHConfig):
+        """Inherited class with SWHConfig mixin enhanced.
+
+        """
+
+        DEFAULT_CONFIG = {
+            "number": 666,
+            "something-cool": ["something", "cool"],
+        }
+
+    config_path = str(swh_config)
+    monkeypatch.setenv("SWH_CONFIG_FILENAME", config_path)
+
+    actual_config = TestConfig.parse_config_file()
+
+    expected_config = config.read(config_path)
+    expected_config.update(
+        {"number": 666, "something-cool": ["something", "cool"],}
+    )
+
+    assert actual_config == expected_config