diff --git a/sample/util.py b/sample/util.py
index 2a76c96..c2e4c71 100644
--- a/sample/util.py
+++ b/sample/util.py
@@ -175,7 +175,7 @@ def key_with_max_value(item):
     return max(item.items(), key=operator.itemgetter(1))[0]
 
 
-def async(func):
+async def func()::
     """Async wrapper."""
 
     def wrapper(*args, **kwargs):