diff --git a/app/routers/events.py b/app/routers/events.py
index 82c0a0a..8855fd3 100644
--- a/app/routers/events.py
+++ b/app/routers/events.py
@@ -462,7 +462,7 @@ async def toggle_interest(event_id: str, user: users.User = Depends(users_token.
     if not event:
         raise HTTPException(status_code=404, detail="Event not found")
 
-    interested_users = getattr(event, "interested_users", [])
+    interested_users = event.interested_users
     user_obj_id = ObjectId(user.id)
 
     if user_obj_id in interested_users:
@@ -471,7 +471,8 @@ async def toggle_interest(event_id: str, user: users.User = Depends(users_token.
     else:
         # Ajouter l’utilisateur
         interested_users.append(user_obj_id)
+    event.interested_users = interested_users
 
-    event_repository.update({"_id": ObjectId(event_id)}, {"$set": {"interested_users": interested_users}})
+    event_repository.save(event)
 
     return {"event_id": event_id, "interested": user_obj_id in interested_users, "interested_count": len(interested_users)}