diff --git a/src/pocketmine/block/utils/SkullType.php b/src/pocketmine/block/utils/SkullType.php
index b53e974b7..38bdc20f6 100644
--- a/src/pocketmine/block/utils/SkullType.php
+++ b/src/pocketmine/block/utils/SkullType.php
@@ -81,7 +81,7 @@ final class SkullType{
 	/** @var int */
 	private $magicNumber;
 
-	public function __construct(string $enumName, string $displayName, int $magicNumber){
+	private function __construct(string $enumName, string $displayName, int $magicNumber){
 		$this->Enum___construct($enumName);
 		$this->displayName = $displayName;
 		$this->magicNumber = $magicNumber;
diff --git a/src/pocketmine/world/sound/NoteInstrument.php b/src/pocketmine/world/sound/NoteInstrument.php
index 622333367..255bfe1f8 100644
--- a/src/pocketmine/world/sound/NoteInstrument.php
+++ b/src/pocketmine/world/sound/NoteInstrument.php
@@ -36,7 +36,7 @@ use pocketmine\utils\EnumTrait;
  * @method static self CLICKS_AND_STICKS()
  * @method static self DOUBLE_BASS()
  */
-class NoteInstrument{
+final class NoteInstrument{
 	use EnumTrait {
 		__construct as Enum___construct;
 	}
@@ -54,7 +54,7 @@ class NoteInstrument{
 	/** @var int */
 	private $magicNumber;
 
-	public function __construct(string $name, int $magicNumber){
+	private function __construct(string $name, int $magicNumber){
 		$this->Enum___construct($name);
 		$this->magicNumber = $magicNumber;
 	}