diff --git a/src/pocketmine/item/Item.php b/src/pocketmine/item/Item.php
index c5ef917a8..356466d68 100644
--- a/src/pocketmine/item/Item.php
+++ b/src/pocketmine/item/Item.php
@@ -65,13 +65,19 @@ class Item implements ItemIds, \JsonSerializable{
 
 	/** @var \SplFixedArray */
 	public static $list = null;
+	/** @var Block|null */
 	protected $block;
+	/** @var int */
 	protected $id;
+	/** @var int */
 	protected $meta;
+	/** @var string */
 	private $tags = "";
+	/** @var CompoundTag|null */
 	private $cachedNBT = null;
+	/** @var int */
 	public $count;
-	protected $durability = 0;
+	/** @var string */
 	protected $name;
 
 	public function canBeActivated(){
@@ -1007,4 +1013,12 @@ class Item implements ItemIds, \JsonSerializable{
 		return $item;
 	}
 
+	public function __clone(){
+		if($this->block !== null){
+			$this->block = clone $this->block;
+		}
+
+		$this->cachedNBT = null;
+	}
+
 }
diff --git a/src/pocketmine/item/ItemBlock.php b/src/pocketmine/item/ItemBlock.php
index 4bcac3f9d..8a61b31aa 100644
--- a/src/pocketmine/item/ItemBlock.php
+++ b/src/pocketmine/item/ItemBlock.php
@@ -37,10 +37,6 @@ class ItemBlock extends Item{
 		$this->block->setDamage($this->meta !== -1 ? $this->meta : 0);
 	}
 
-	public function __clone(){
-		$this->block = clone $this->block;
-	}
-
 	public function getBlock() : Block{
 		return $this->block;
 	}