diff --git a/tests/conftest.py b/tests/conftest.py
index c9e3f84..2ccc132 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -24,14 +24,14 @@
 
     Additionally mocks any non-existing modules specified in the dotted path.
     """
+
     def _mock_non_existent_module(path):
-        parts = path.split('.')
+        parts = path.split(".")
         partial = []
         for part in parts:
             partial.append(part)
-            current_module = '.'.join(partial)
+            current_module = ".".join(partial)
             if current_module not in sys.modules:
-                monkeypatch.setitem(
-                    sys.modules, current_module, mock.MagicMock())
+                monkeypatch.setitem(sys.modules, current_module, mock.MagicMock())
 
     return _mock_non_existent_module