diff --git a/utils/redis.py b/utils/redis.py
index 0d3eb20..545b330 100644
--- a/utils/redis.py
+++ b/utils/redis.py
@@ -3,6 +3,7 @@ import hashlib
 import random
 import secrets
 from datetime import datetime, timedelta
+from typing import Optional
 from urllib.parse import parse_qsl, urlencode, urlparse, urlunparse
 
 from redis.exceptions import RedisError
@@ -92,7 +93,7 @@ class OnlineClassTokenManager(RedisConfig):
         seed = f"{course_id}:{user_identifier}:{secrets.token_urlsafe(16)}"
         return hashlib.sha256(seed.encode()).hexdigest()
 
-    def store_token(self, token: str, payload: dict, ttl: int | None = None) -> None:
+    def store_token(self, token: str, payload: dict, ttl: Optional[int] = None) -> None:
         data = {
             **payload,
             "generated_at": datetime.utcnow().isoformat() + "Z",
@@ -109,7 +110,7 @@ class OnlineClassTokenManager(RedisConfig):
         self.redis.delete(self._build_key(token))
 
     @staticmethod
-    def build_entry_url(token: str, base_url: str | None = None) -> str:
+    def build_entry_url(token: str, base_url: Optional[str] = None) -> str:
         base = base_url or getattr(settings, "ONLINE_CLASS_FRONTEND_DOMAIN", getattr(settings, "SITE_DOMAIN", ""))
         if not base:
             return f"?token={token}"