diff --git a/ecs/jskult-webapp/src/model/internal/session.py b/ecs/jskult-webapp/src/model/internal/session.py
index f2495c2a..99233a1e 100644
--- a/ecs/jskult-webapp/src/model/internal/session.py
+++ b/ecs/jskult-webapp/src/model/internal/session.py
@@ -32,7 +32,7 @@ class UserSession(DynamoDBTableModel):
     def new_record_expiration_time(cls):
         last_access_time = datetime.datetime.fromtimestamp(cls.new_last_access_time())
         # 1時間後に有効期限切れにする
-        return (last_access_time + datetime.timedelta(hours=1)).timestamp().timestamp()
+        return (last_access_time + datetime.timedelta(hours=1)).timestamp()
 
     @classmethod
     def new(