diff --git a/docs_src/handling_errors/tutorial008.py b/docs_src/handling_errors/tutorial008.py
index b05652647..fc227126a 100644
--- a/docs_src/handling_errors/tutorial008.py
+++ b/docs_src/handling_errors/tutorial008.py
@@ -18,7 +18,7 @@ class UnsupportedFileTypeError(HTTPException):
 
 
 @app.exception_handler((FileTooLargeError, UnsupportedFileTypeError))
-def custom_exception_handler(request: Request, exc: HTTPException):
+async def custom_exception_handler(request: Request, exc: HTTPException):
     return JSONResponse(
         status_code=exc.status_code,
         content={"error": exc.detail, "hint": "Need help? Contact support@example.com"},