diff --git a/matrix_appservice_kakaotalk/puppet.py b/matrix_appservice_kakaotalk/puppet.py
index 48f0c68..8a525eb 100644
--- a/matrix_appservice_kakaotalk/puppet.py
+++ b/matrix_appservice_kakaotalk/puppet.py
@@ -204,8 +204,9 @@ class Puppet(DBPuppet, BasePuppet):
             return True
         return False
 
+    @classmethod
     async def reupload_avatar(
-        self,
+        cls,
         source: u.User,
         intent: IntentAPI,
         url: str,
@@ -215,7 +216,7 @@ class Puppet(DBPuppet, BasePuppet):
             data = await resp.read()
         mime = magic.mimetype(data)
         return await intent.upload_media(
-            data, mime_type=mime, async_upload=self.config["homeserver.async_media"]
+            data, mime_type=mime, async_upload=cls.config["homeserver.async_media"]
         )
 
     async def _update_photo(self, source: u.User, photo_id: str) -> bool: