diff --git a/src/pocketmine/CoreConstants.php b/src/pocketmine/CoreConstants.php
index 7dd0e50a4..091c43898 100644
--- a/src/pocketmine/CoreConstants.php
+++ b/src/pocketmine/CoreConstants.php
@@ -23,6 +23,10 @@ declare(strict_types=1);
 
 namespace pocketmine;
 
+use function define;
+use function defined;
+use function dirname;
+
 // composer autoload doesn't use require_once and also pthreads can inherit things
 if(defined('pocketmine\_CORE_CONSTANTS_INCLUDED')){
 	return;
diff --git a/src/pocketmine/Thread.php b/src/pocketmine/Thread.php
index 389eb9550..86d923316 100644
--- a/src/pocketmine/Thread.php
+++ b/src/pocketmine/Thread.php
@@ -23,6 +23,8 @@ declare(strict_types=1);
 
 namespace pocketmine;
 
+use const PTHREADS_INHERIT_ALL;
+
 /**
  * This class must be extended by all custom threading classes
  */
@@ -78,7 +80,7 @@ abstract class Thread extends \Thread{
 	 *
 	 * @return bool
 	 */
-	public function start(?int $options = \PTHREADS_INHERIT_ALL){
+	public function start(?int $options = PTHREADS_INHERIT_ALL){
 		ThreadManager::getInstance()->add($this);
 
 		if($this->getClassLoader() === null){
diff --git a/src/pocketmine/VersionInfo.php b/src/pocketmine/VersionInfo.php
index 6e4ec054f..db462770c 100644
--- a/src/pocketmine/VersionInfo.php
+++ b/src/pocketmine/VersionInfo.php
@@ -23,6 +23,8 @@ declare(strict_types=1);
 
 namespace pocketmine;
 
+use function defined;
+
 // composer autoload doesn't use require_once and also pthreads can inherit things
 // TODO: drop this file and use a final class with constants
 if(defined('pocketmine\_VERSION_INFO_INCLUDED')){
diff --git a/src/pocketmine/Worker.php b/src/pocketmine/Worker.php
index b7b551c29..3687e80b4 100644
--- a/src/pocketmine/Worker.php
+++ b/src/pocketmine/Worker.php
@@ -23,6 +23,8 @@ declare(strict_types=1);
 
 namespace pocketmine;
 
+use const PTHREADS_INHERIT_ALL;
+
 /**
  * This class must be extended by all custom threading classes
  */
@@ -78,7 +80,7 @@ abstract class Worker extends \Worker{
 	 *
 	 * @return bool
 	 */
-	public function start(?int $options = \PTHREADS_INHERIT_ALL){
+	public function start(?int $options = PTHREADS_INHERIT_ALL){
 		ThreadManager::getInstance()->add($this);
 
 		if($this->getClassLoader() === null){
diff --git a/src/pocketmine/network/mcpe/NetworkBinaryStream.php b/src/pocketmine/network/mcpe/NetworkBinaryStream.php
index c2890bfa2..627a6eb15 100644
--- a/src/pocketmine/network/mcpe/NetworkBinaryStream.php
+++ b/src/pocketmine/network/mcpe/NetworkBinaryStream.php
@@ -27,7 +27,6 @@ namespace pocketmine\network\mcpe;
 
 use pocketmine\entity\Attribute;
 use pocketmine\entity\Entity;
-use pocketmine\entity\Skin;
 use pocketmine\item\Durable;
 use pocketmine\item\Item;
 use pocketmine\item\ItemFactory;
diff --git a/src/pocketmine/network/mcpe/protocol/BatchPacket.php b/src/pocketmine/network/mcpe/protocol/BatchPacket.php
index 7124f7515..b9e715586 100644
--- a/src/pocketmine/network/mcpe/protocol/BatchPacket.php
+++ b/src/pocketmine/network/mcpe/protocol/BatchPacket.php
@@ -25,7 +25,6 @@ namespace pocketmine\network\mcpe\protocol;
 
 #include <rules/DataPacket.h>
 
-
 use pocketmine\network\mcpe\NetworkBinaryStream;
 use pocketmine\network\mcpe\NetworkSession;
 use function assert;