diff --git a/mongoengine/errors.py b/mongoengine/errors.py
index 52144594..d789b2a1 100644
--- a/mongoengine/errors.py
+++ b/mongoengine/errors.py
@@ -16,9 +16,11 @@ __all__ = (
     "DeprecatedError",
 )
 
+
 class MongoEngineException(Exception):
     pass
 
+
 class NotRegistered(MongoEngineException):
     pass