diff --git a/src/pocketmine/scheduler/AsyncPool.php b/src/pocketmine/scheduler/AsyncPool.php
index b8069501c..a4bdb55d1 100644
--- a/src/pocketmine/scheduler/AsyncPool.php
+++ b/src/pocketmine/scheduler/AsyncPool.php
@@ -142,7 +142,7 @@ class AsyncPool{
 		Timings::$schedulerAsyncTimer->startTiming();
 
 		foreach($this->tasks as $task){
-			if($task->progressUpdates !== null){
+			if(!$task->isGarbage() and $task->progressUpdates !== null){
 				if($task->progressUpdates->count() !== 0){
 					$progress = $task->progressUpdates->shift();
 					$task->onProgressUpdate($this->server, $progress);