diff --git a/rcon/async_rcon.py b/rcon/async_rcon.py
index c2aa82c..97f3acf 100644
--- a/rcon/async_rcon.py
+++ b/rcon/async_rcon.py
@@ -10,7 +10,7 @@ from rcon.proto import Packet, Type
 __all__ = ['rcon']
 
 
-async def close(socket: IO) -> None
+async def close(socket: IO) -> None:
     """Close socket asynchronously"""
 
     socket.close()