diff --git a/src/pocketmine/scheduler/AsyncWorker.php b/src/pocketmine/scheduler/AsyncWorker.php
index 81e313821..7b8532feb 100644
--- a/src/pocketmine/scheduler/AsyncWorker.php
+++ b/src/pocketmine/scheduler/AsyncWorker.php
@@ -38,9 +38,7 @@ class AsyncWorker extends Worker{
 
 	public function run(){
 		$this->registerClassLoader();
-		if(MainLogger::getLogger() === null){
-			$this->logger->registerStatic();
-		}
+		$this->logger->registerStatic();
 
 		gc_enable();
 		ini_set("memory_limit", '-1');
diff --git a/src/pocketmine/utils/MainLogger.php b/src/pocketmine/utils/MainLogger.php
index 3cad79782..818e7976a 100644
--- a/src/pocketmine/utils/MainLogger.php
+++ b/src/pocketmine/utils/MainLogger.php
@@ -54,22 +54,22 @@ class MainLogger extends \AttachableThreadedLogger{
 	}
 
 	/**
-	 * @return MainLogger|null
+	 * @return MainLogger
 	 */
-	public static function getLogger(){
+	public static function getLogger() : MainLogger{
 		return static::$logger;
 	}
 
 	/**
-	 * Assigns the MainLogger instance to the {@link MainLogger#logger} static property. Because static properties are
-	 * thread-local, this must be called from the body of every Thread if you want the logger to be accessible via
-	 * {@link MainLogger#getLogger}.
+	 * Assigns the MainLogger instance to the {@link MainLogger#logger} static property.
+	 *
+	 * WARNING: Because static properties are thread-local, this MUST be called from the body of every Thread if you
+	 * want the logger to be accessible via {@link MainLogger#getLogger}.
 	 */
 	public function registerStatic(){
-		if(static::$logger instanceof MainLogger){
-			throw new \RuntimeException("MainLogger has been already registered");
+		if(static::$logger === null){
+			static::$logger = $this;
 		}
-		static::$logger = $this;
 	}
 
 	public function emergency($message){
diff --git a/tests/plugins/PocketMine-TesterPlugin b/tests/plugins/PocketMine-TesterPlugin
index e09e6e945..69608aae7 160000
--- a/tests/plugins/PocketMine-TesterPlugin
+++ b/tests/plugins/PocketMine-TesterPlugin
@@ -1 +1 @@
-Subproject commit e09e6e945db84f07050ccadc54463e8beb8e32ba
+Subproject commit 69608aae7e95f003c9c02b1830705af8e9f82015