diff --git a/src/pocketmine/inventory/transaction/action/SlotChangeAction.php b/src/pocketmine/inventory/transaction/action/SlotChangeAction.php
index a63e98cbb..e4756876e 100644
--- a/src/pocketmine/inventory/transaction/action/SlotChangeAction.php
+++ b/src/pocketmine/inventory/transaction/action/SlotChangeAction.php
@@ -76,7 +76,6 @@ class SlotChangeAction extends InventoryAction{
 	 */
 	public function isValid(Player $source) : bool{
 		return (
-			$this->inventorySlot >= 0 and
 			$this->inventory->slotExists($this->inventorySlot) and
 			$this->inventory->getItem($this->inventorySlot)->equalsExact($this->sourceItem)
 		);