diff --git a/unipay/providers/transfer.py b/unipay/providers/transfer.py
index 08050b8..9b755e7 100644
--- a/unipay/providers/transfer.py
+++ b/unipay/providers/transfer.py
@@ -1,5 +1,6 @@
 import re
 from random import randint
+from typing import Any, Dict, Optional
 import poplib
 from appPublic.log import debug
 from appPublic.dictObject import DictObject