diff --git a/docs/async.md b/docs/async.md
index 1cd51b00..3238097a 100644
--- a/docs/async.md
+++ b/docs/async.md
@@ -169,7 +169,7 @@ from starlette.responses import HTMLResponse
 from starlette.routing import Route
 
 
-async def hello():
+async def hello(request):
     return HTMLResponse("Hello World!")