diff --git a/src/pocketmine/Thread.php b/src/pocketmine/Thread.php
index 2a838154f..2c539b90e 100644
--- a/src/pocketmine/Thread.php
+++ b/src/pocketmine/Thread.php
@@ -30,6 +30,9 @@ abstract class Thread extends \Thread{
 
 	/** @var \ClassLoader */
 	protected $classLoader;
+	/** @var string|null */
+	protected $composerAutoloaderPath;
+
 	protected $isKilled = false;
 
 	public function getClassLoader(){
@@ -37,6 +40,8 @@ abstract class Thread extends \Thread{
 	}
 
 	public function setClassLoader(\ClassLoader $loader = null){
+		$this->composerAutoloaderPath = \pocketmine\COMPOSER_AUTOLOADER_PATH;
+
 		if($loader === null){
 			$loader = Server::getInstance()->getLoader();
 		}
@@ -51,7 +56,9 @@ abstract class Thread extends \Thread{
 	 * (unless you are using a custom autoloader).
 	 */
 	public function registerClassLoader(){
-		require(\pocketmine\PATH . "vendor/autoload.php");
+		if($this->composerAutoloaderPath !== null){
+			require $this->composerAutoloaderPath;
+		}
 		if($this->classLoader !== null){
 			$this->classLoader->register(false);
 		}
diff --git a/src/pocketmine/Worker.php b/src/pocketmine/Worker.php
index f63f4b2ed..f79f502d8 100644
--- a/src/pocketmine/Worker.php
+++ b/src/pocketmine/Worker.php
@@ -30,6 +30,8 @@ abstract class Worker extends \Worker{
 
 	/** @var \ClassLoader */
 	protected $classLoader;
+	/** @var string|null */
+	protected $composerAutoloaderPath;
 
 	protected $isKilled = false;
 
@@ -38,6 +40,8 @@ abstract class Worker extends \Worker{
 	}
 
 	public function setClassLoader(\ClassLoader $loader = null){
+		$this->composerAutoloaderPath = \pocketmine\COMPOSER_AUTOLOADER_PATH;
+
 		if($loader === null){
 			$loader = Server::getInstance()->getLoader();
 		}
@@ -52,7 +56,9 @@ abstract class Worker extends \Worker{
 	 * (unless you are using a custom autoloader).
 	 */
 	public function registerClassLoader(){
-		require(\pocketmine\PATH . "vendor/autoload.php");
+		if($this->composerAutoloaderPath !== null){
+			require $this->composerAutoloaderPath;
+		}
 		if($this->classLoader !== null){
 			$this->classLoader->register(false);
 		}