diff --git a/matrix_appservice_kakaotalk/user.py b/matrix_appservice_kakaotalk/user.py
index 2cf2c0d..77f27cc 100644
--- a/matrix_appservice_kakaotalk/user.py
+++ b/matrix_appservice_kakaotalk/user.py
@@ -471,7 +471,7 @@ class User(DBUser, BaseUser):
             if self.config["bridge.sync_on_startup"] or not is_startup:
                 sync_count = self.config["bridge.initial_chat_sync"]
             else:
-                sync_count = None
+                sync_count = 0
             await self.connect_and_sync(sync_count, force_sync=False)
         else:
             await self.send_bridge_notice(