diff --git a/files/lib/data/room/RoomCache.class.php b/files/lib/data/room/RoomCache.class.php
index b7f4f65..bcba95e 100644
--- a/files/lib/data/room/RoomCache.class.php
+++ b/files/lib/data/room/RoomCache.class.php
@@ -21,7 +21,7 @@
 /**
  * Manages the room cache.
  */
-class RoomCache extends SingletonFactory
+final class RoomCache extends SingletonFactory
 {
     /**
      * List of cached rooms.