diff --git a/src/pocketmine/Player.php b/src/pocketmine/Player.php
index 6d00a8f81..f3b8e0dd1 100644
--- a/src/pocketmine/Player.php
+++ b/src/pocketmine/Player.php
@@ -153,6 +153,7 @@ use pocketmine\network\mcpe\protocol\StartGamePacket;
 use pocketmine\network\mcpe\protocol\TakeItemEntityPacket;
 use pocketmine\network\mcpe\protocol\TextPacket;
 use pocketmine\network\mcpe\protocol\TransferPacket;
+use pocketmine\network\mcpe\protocol\types\ContainerIds;
 use pocketmine\network\mcpe\protocol\UpdateAttributesPacket;
 use pocketmine\network\mcpe\protocol\UpdateBlockPacket;
 use pocketmine\network\mcpe\protocol\UseItemPacket;
@@ -2761,21 +2762,21 @@ class Player extends Human implements CommandSender, InventoryHolder, ChunkLoade
 		}
 
 		switch($packet->windowid){
-			case ContainerSetContentPacket::SPECIAL_INVENTORY: //Normal inventory change
+			case ContainerIds::INVENTORY: //Normal inventory change
 				if($packet->slot >= $this->inventory->getSize()){
 					return false;
 				}
 
 				$transaction = new BaseTransaction($this->inventory, $packet->slot, $this->inventory->getItem($packet->slot), $packet->item);
 				break;
-			case ContainerSetContentPacket::SPECIAL_ARMOR: //Armour change
+			case ContainerIds::ARMOR: //Armour change
 				if($packet->slot >= 4){
 					return false;
 				}
 
 				$transaction = new BaseTransaction($this->inventory, $packet->slot + $this->inventory->getSize(), $this->inventory->getArmorItem($packet->slot), $packet->item);
 				break;
-			case ContainerSetContentPacket::SPECIAL_HOTBAR: //Hotbar link update
+			case ContainerIds::HOTBAR: //Hotbar link update
 				//hotbarSlot 0-8, slot 9-44
 				$this->inventory->setHotbarSlotIndex($packet->hotbarSlot, $packet->slot - 9);
 				return true;
diff --git a/src/pocketmine/inventory/PlayerInventory.php b/src/pocketmine/inventory/PlayerInventory.php
index b7b5bf41a..994cfd5f7 100644
--- a/src/pocketmine/inventory/PlayerInventory.php
+++ b/src/pocketmine/inventory/PlayerInventory.php
@@ -32,6 +32,7 @@ use pocketmine\network\mcpe\protocol\ContainerSetContentPacket;
 use pocketmine\network\mcpe\protocol\ContainerSetSlotPacket;
 use pocketmine\network\mcpe\protocol\MobArmorEquipmentPacket;
 use pocketmine\network\mcpe\protocol\MobEquipmentPacket;
+use pocketmine\network\mcpe\protocol\types\ContainerIds;
 use pocketmine\Player;
 use pocketmine\Server;
 
@@ -238,7 +239,7 @@ class PlayerInventory extends BaseInventory{
 		$pk->item = $item;
 		$pk->inventorySlot = $this->getHeldItemSlot();
 		$pk->hotbarSlot = $this->getHeldItemIndex();
-		$pk->windowId = ContainerSetContentPacket::SPECIAL_INVENTORY;
+		$pk->windowId = ContainerIds::INVENTORY;
 
 		if(!is_array($target)){
 			$target->dataPacket($pk);
@@ -424,7 +425,7 @@ class PlayerInventory extends BaseInventory{
 		foreach($target as $player){
 			if($player === $this->getHolder()){
 				$pk2 = new ContainerSetContentPacket();
-				$pk2->windowid = ContainerSetContentPacket::SPECIAL_ARMOR;
+				$pk2->windowid = ContainerIds::ARMOR;
 				$pk2->slots = $armor;
 				$pk2->targetEid = $player->getId();
 				$player->dataPacket($pk2);
@@ -473,7 +474,7 @@ class PlayerInventory extends BaseInventory{
 			if($player === $this->getHolder()){
 				/** @var Player $player */
 				$pk2 = new ContainerSetSlotPacket();
-				$pk2->windowid = ContainerSetContentPacket::SPECIAL_ARMOR;
+				$pk2->windowid = ContainerIds::ARMOR;
 				$pk2->slot = $index - $this->getSize();
 				$pk2->item = $this->getItem($index);
 				$player->dataPacket($pk2);
@@ -523,7 +524,7 @@ class PlayerInventory extends BaseInventory{
 
 	public function sendCreativeContents(){
 		$pk = new ContainerSetContentPacket();
-		$pk->windowid = ContainerSetContentPacket::SPECIAL_CREATIVE;
+		$pk->windowid = ContainerIds::CREATIVE;
 		if($this->getHolder()->getGamemode() === Player::CREATIVE){
 			foreach(Item::getCreativeItems() as $i => $item){
 				$pk->slots[$i] = clone $item;
diff --git a/src/pocketmine/network/mcpe/protocol/ContainerSetContentPacket.php b/src/pocketmine/network/mcpe/protocol/ContainerSetContentPacket.php
index 62723d4f3..bb47539b7 100644
--- a/src/pocketmine/network/mcpe/protocol/ContainerSetContentPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/ContainerSetContentPacket.php
@@ -27,17 +27,11 @@ namespace pocketmine\network\mcpe\protocol;
 
 
 use pocketmine\network\mcpe\NetworkSession;
+use pocketmine\network\mcpe\protocol\types\ContainerIds;
 
 class ContainerSetContentPacket extends DataPacket{
 	const NETWORK_ID = ProtocolInfo::CONTAINER_SET_CONTENT_PACKET;
 
-	const SPECIAL_INVENTORY = 0;
-	const SPECIAL_OFFHAND = 0x77;
-	const SPECIAL_ARMOR = 0x78;
-	const SPECIAL_CREATIVE = 0x79;
-	const SPECIAL_HOTBAR = 0x7a;
-	const SPECIAL_FIXED_INVENTORY = 0x7b;
-
 	public $windowid;
 	public $targetEid;
 	public $slots = [];
@@ -70,7 +64,7 @@ class ContainerSetContentPacket extends DataPacket{
 		foreach($this->slots as $slot){
 			$this->putSlot($slot);
 		}
-		if($this->windowid === self::SPECIAL_INVENTORY and count($this->hotbar) > 0){
+		if($this->windowid === ContainerIds::INVENTORY and count($this->hotbar) > 0){
 			$this->putUnsignedVarInt(count($this->hotbar));
 			foreach($this->hotbar as $slot){
 				$this->putVarInt($slot);
diff --git a/src/pocketmine/network/mcpe/protocol/types/ContainerIds.php b/src/pocketmine/network/mcpe/protocol/types/ContainerIds.php
new file mode 100644
index 000000000..640dea519
--- /dev/null
+++ b/src/pocketmine/network/mcpe/protocol/types/ContainerIds.php
@@ -0,0 +1,38 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\network\mcpe\protocol\types;
+
+interface ContainerIds{
+
+	const NONE = -1;
+	const INVENTORY = 0;
+	const FIRST = 1;
+	const LAST = 100;
+	const OFFHAND = 119;
+	const ARMOR = 120;
+	const CREATIVE = 121;
+	const HOTBAR = 122;
+	const FIXED_INVENTORY = 123;
+
+}
\ No newline at end of file