From 42913389c01555b1e7438c28939ac093de90d809 Mon Sep 17 00:00:00 2001
From: Alex Root Junior <jroot.junior@gmail.com>
Date: Wed, 24 Oct 2018 22:39:34 +0300
Subject: [PATCH] Resolve decorated callbacks in spec filter

---
 aiogram/dispatcher/handler.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/aiogram/dispatcher/handler.py b/aiogram/dispatcher/handler.py
index 7be6b3d4..2caf80d8 100644
--- a/aiogram/dispatcher/handler.py
+++ b/aiogram/dispatcher/handler.py
@@ -14,6 +14,9 @@ class CancelHandler(Exception):
 
 
 def _check_spec(func: callable, kwargs: dict):
+    while hasattr(func, '__wrapped__'):  # Try to resolve decorated callbacks
+        func = func.__wrapped__
+
     spec = inspect.getfullargspec(func)
     if spec.varkw:
         return kwargs