diff --git a/src/pocketmine/block/Block.php b/src/pocketmine/block/Block.php
index a8813f885..dfafecf0f 100644
--- a/src/pocketmine/block/Block.php
+++ b/src/pocketmine/block/Block.php
@@ -67,7 +67,7 @@ class Block extends Position implements BlockIds, Metadatable{
 	protected $itemId;
 
 	/** @var AxisAlignedBB */
-	public $boundingBox = null;
+	protected $boundingBox = null;
 
 
 	/** @var AxisAlignedBB[]|null */