diff --git a/rental_backend/routes/rental_session.py b/rental_backend/routes/rental_session.py
index aad6ae8..e574024 100644
--- a/rental_backend/routes/rental_session.py
+++ b/rental_backend/routes/rental_session.py
@@ -207,7 +207,7 @@ async def start_rental_session(
         now = datetime.datetime.now(tz=datetime.timezone.utc)
         new_deadline = now.replace(hour=settings.BASE_OVERDUE, minute=0, second=0, microsecond=0)
         if now > new_deadline:
-            new_deadline = now.replace(day=now.day + 1, hour=settings.BASE_OVERDUE, minute=0, second=0, microsecond=0)
+            new_deadline += datetime.timedelta(days=1)
         info_for_update["deadline_ts"] = new_deadline
 
     updated_session = RentalSession.update(**info_for_update)