diff --git a/src/thread/Thread.php b/src/thread/Thread.php
index 140dba225..caf2edd26 100644
--- a/src/thread/Thread.php
+++ b/src/thread/Thread.php
@@ -31,7 +31,7 @@ use const PTHREADS_INHERIT_ALL;
 abstract class Thread extends \Thread{
 	use CommonThreadPartsTrait;
 
-	public function start(?int $options = PTHREADS_INHERIT_ALL) : bool{
+	public function start(int $options = PTHREADS_INHERIT_ALL) : bool{
 		//this is intentionally not traitified
 		ThreadManager::getInstance()->add($this);
 
diff --git a/src/thread/Worker.php b/src/thread/Worker.php
index 0874ad547..e3e4acdf3 100644
--- a/src/thread/Worker.php
+++ b/src/thread/Worker.php
@@ -31,7 +31,7 @@ use const PTHREADS_INHERIT_ALL;
 abstract class Worker extends \Worker{
 	use CommonThreadPartsTrait;
 
-	public function start(?int $options = PTHREADS_INHERIT_ALL) : bool{
+	public function start(int $options = PTHREADS_INHERIT_ALL) : bool{
 		//this is intentionally not traitified
 		ThreadManager::getInstance()->add($this);