diff --git a/mashumaro/serializer/base/dict.py b/mashumaro/serializer/base/dict.py
index bd68bbfd..fec23ad4 100644
--- a/mashumaro/serializer/base/dict.py
+++ b/mashumaro/serializer/base/dict.py
@@ -35,4 +35,6 @@ def from_dict(
         pass
 
 
-__all__ = [DataClassDictMixin]
+__all__ = [
+    'DataClassDictMixin'
+]