diff --git a/tests/test_config_utils.py b/tests/test_config_utils.py
index eb4eb5e5..ea58f61a 100644
--- a/tests/test_config_utils.py
+++ b/tests/test_config_utils.py
@@ -12,6 +12,13 @@ ORIGINAL_CONFIG = copy.deepcopy(bigchaindb._config)
 
 @pytest.fixture
 def ignore_local_config_file(monkeypatch):
+    """
+    This fixture's purpose is to override the one under
+    :module:`tests/conftest.py` so that the original behaviour of
+    :func:`bigchaindb.config_utils.file_config` is restored, so that it can be
+    tested.
+
+    """
     from bigchaindb.config_utils import file_config
     monkeypatch.setattr('bigchaindb.config_utils.file_config', file_config)