diff --git a/src/pocketmine/Player.php b/src/pocketmine/Player.php
index e0485e1ab..662c4ba02 100644
--- a/src/pocketmine/Player.php
+++ b/src/pocketmine/Player.php
@@ -207,8 +207,8 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	protected $xuid = "";
 
 	protected $windowCnt = 2;
-	/** @var \SplObjectStorage<Inventory> */
-	protected $windows;
+	/** @var int[] */
+	protected $windows = [];
 	/** @var Inventory[] */
 	protected $windowIndex = [];
 	/** @var bool[] */
@@ -685,7 +685,6 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	 */
 	public function __construct(SourceInterface $interface, $clientID, string $ip, int $port){
 		$this->interface = $interface;
-		$this->windows = new \SplObjectStorage();
 		$this->perm = new PermissibleBase($this);
 		$this->namedtag = new CompoundTag();
 		$this->server = Server::getInstance();
@@ -3327,7 +3326,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 				}
 
 				$this->removeAllWindows(true);
-				$this->windows = null;
+				$this->windows = [];
 				$this->windowIndex = [];
 				$this->cursorInventory = null;
 				$this->craftingGrid = null;
@@ -3723,13 +3722,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	 * @return int
 	 */
 	public function getWindowId(Inventory $inventory) : int{
-		if($this->windows->contains($inventory)){
-			/** @var int $id */
-			$id = $this->windows[$inventory];
-			return $id;
-		}
-
-		return ContainerIds::NONE;
+		return $this->windows[spl_object_hash($inventory)] ?? ContainerIds::NONE;
 	}
 
 	/**
@@ -3765,7 +3758,7 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 			$cnt = $forceId;
 		}
 		$this->windowIndex[$cnt] = $inventory;
-		$this->windows->attach($inventory, $cnt);
+		$this->windows[spl_object_hash($inventory)] = $cnt;
 		if($inventory->open($this)){
 			if($isPermanent){
 				$this->permanentWindows[$cnt] = true;
@@ -3787,15 +3780,14 @@ class Player extends Human implements CommandSender, ChunkLoader, IPlayer{
 	 * @throws \BadMethodCallException if trying to remove a fixed inventory window without the `force` parameter as true
 	 */
 	public function removeWindow(Inventory $inventory, bool $force = false){
-		if($this->windows->contains($inventory)){
+		if(isset($this->windows[$hash = spl_object_hash($inventory)])){
 			/** @var int $id */
-			$id = $this->windows[$inventory];
+			$id = $this->windows[$hash];
 			if(!$force and isset($this->permanentWindows[$id])){
 				throw new \BadMethodCallException("Cannot remove fixed window $id (" . get_class($inventory) . ") from " . $this->getName());
 			}
-			$this->windows->detach($this->windowIndex[$id]);
-			unset($this->windowIndex[$id]);
-			unset($this->permanentWindows[$id]);
+
+			unset($this->windows[$hash], $this->windowIndex[$id], $this->permanentWindows[$id]);
 		}
 
 		$inventory->close($this);