diff --git a/src/block/tile/BrewingStand.php b/src/block/tile/BrewingStand.php
index 62814e528..6d34ecfb8 100644
--- a/src/block/tile/BrewingStand.php
+++ b/src/block/tile/BrewingStand.php
@@ -54,7 +54,7 @@ class BrewingStand extends Spawnable implements Container, Nameable{
 	public function __construct(World $world, Vector3 $pos){
 		parent::__construct($world, $pos);
 		$this->inventory = new BrewingStandInventory($this->pos);
-		$this->inventory->addChangeListeners(CallbackInventoryChangeListener::onAnyChange(function(Inventory $unused){
+		$this->inventory->addChangeListeners(CallbackInventoryChangeListener::onAnyChange(function(Inventory $unused) : void{
 			$this->pos->getWorld()->scheduleDelayedBlockUpdate($this->pos, 1);
 		}));
 	}