diff --git a/app.py b/app.py
index f1cdc58..82dc3dd 100644
--- a/app.py
+++ b/app.py
@@ -11,6 +11,7 @@ import aiohttp
 from aiohttp import web
 from dotenv import load_dotenv
 from pywebpush import webpush, WebPushException
+from cryptography.hazmat.backends import default_backend
 from cryptography.hazmat.primitives import serialization
 from cryptography.hazmat.primitives.asymmetric import ec