diff --git a/amanobot/__init__.py b/amanobot/__init__.py
index 85f9015..6da740f 100644
--- a/amanobot/__init__.py
+++ b/amanobot/__init__.py
@@ -805,7 +805,8 @@ def kickChatMember(self, chat_id, user_id,
         p = _strip(locals())
         return self._api_request('kickChatMember', _rectify(p))
 
-    def unbanChatMember(self, chat_id, user_id):
+    def unbanChatMember(self, chat_id, user_id,
+                        only_if_banned=None):
         """ See: https://core.telegram.org/bots/api#unbanchatmember """
         p = _strip(locals())
         return self._api_request('unbanChatMember', _rectify(p))
diff --git a/amanobot/aio/__init__.py b/amanobot/aio/__init__.py
index 491eb05..9843f35 100644
--- a/amanobot/aio/__init__.py
+++ b/amanobot/aio/__init__.py
@@ -389,7 +389,8 @@ async def kickChatMember(self, chat_id, user_id,
         p = _strip(locals())
         return await self._api_request('kickChatMember', _rectify(p))
 
-    async def unbanChatMember(self, chat_id, user_id):
+    async def unbanChatMember(self, chat_id, user_id,
+                              only_if_banned=None):
         """ See: https://core.telegram.org/bots/api#unbanchatmember """
         p = _strip(locals())
         return await self._api_request('unbanChatMember', _rectify(p))