diff --git a/src/pocketmine/utils/ServerKiller.php b/src/pocketmine/utils/ServerKiller.php
index 2e3326ebb..34333f463 100644
--- a/src/pocketmine/utils/ServerKiller.php
+++ b/src/pocketmine/utils/ServerKiller.php
@@ -32,7 +32,9 @@ class ServerKiller extends Thread{
 	}
 
 	public function run(){
-		sleep($this->time);
+		$this->synchronized(function(){
+			$this->wait($this->time * 1000000);
+		});
 		echo "\nTook too long to stop, server was killed forcefully!\n";
 		@\pocketmine\kill(getmypid());
 	}