diff --git a/src/inventory/PlayerInventory.php b/src/inventory/PlayerInventory.php
index 1da30d2e9..baeecb5af 100644
--- a/src/inventory/PlayerInventory.php
+++ b/src/inventory/PlayerInventory.php
@@ -49,7 +49,7 @@ class PlayerInventory extends SimpleInventory{
 	}
 
 	public function isHotbarSlot(int $slot) : bool{
-		return $slot >= 0 && $slot <= $this->getHotbarSize();
+		return $slot >= 0 && $slot < $this->getHotbarSize();
 	}
 
 	/**