diff --git a/bemani/common/card.py b/bemani/common/card.py
index 54f4cd8..3e8bea7 100644
--- a/bemani/common/card.py
+++ b/bemani/common/card.py
@@ -3,6 +3,7 @@ from typing_extensions import Final
 
 from Crypto.Cipher import DES3
 
+
 class CardCipherException(Exception):
     pass