diff --git a/weblate/utils/lock.py b/weblate/utils/lock.py
index 5704bf952b69..05aa5ed87fb4 100644
--- a/weblate/utils/lock.py
+++ b/weblate/utils/lock.py
@@ -6,9 +6,11 @@
 
 import os
 from contextlib import suppress
+from typing import cast
 
 import sentry_sdk
 from django.core.cache import cache
+from django_redis.cache import RedisCache
 from filelock import FileLock, Timeout
 from redis_lock import AlreadyAcquired, NotAcquired
 
@@ -29,7 +31,7 @@ def __init__(
         key: int,
         slug: str,
         cache_template: str = "lock:{scope}:{key}",
-        file_template: str | None = "{slug}-{scope}.lock",
+        file_template: str = "{slug}-{scope}.lock",
         timeout: int = 1,
     ) -> None:
         self._timeout = timeout
@@ -41,7 +43,7 @@ def __init__(
         if is_redis_cache():
             # Prefer Redis locking as it works distributed
             self._name = self._format_template(cache_template)
-            self._lock = cache.lock(
+            self._lock = cast(RedisCache, cache).lock(
                 key=self._name,
                 expire=3600,
                 auto_renewal=True,