diff --git a/src/block/utils/DyeColor.php b/src/block/utils/DyeColor.php
index 764e13833..80cb08767 100644
--- a/src/block/utils/DyeColor.php
+++ b/src/block/utils/DyeColor.php
@@ -57,8 +57,8 @@ final class DyeColor{
 	/** @var DyeColor[] */
 	private static $numericIdMap = [];
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new DyeColor("white", "White", 0, new Color(0xf0, 0xf0, 0xf0)),
 			new DyeColor("orange", "Orange", 1, new Color(0xf9, 0x80, 0x1d)),
 			new DyeColor("magenta", "Magenta", 2, new Color(0xc7, 0x4e, 0xbd)),
@@ -75,7 +75,7 @@ final class DyeColor{
 			new DyeColor("green", "Green", 13, new Color(0x5e, 0x7c, 0x16)),
 			new DyeColor("red", "Red", 14, new Color(0xb0, 0x2e, 0x26)),
 			new DyeColor("black", "Black", 15, new Color(0x1d, 0x1d, 0x21)),
-		];
+		);
 	}
 
 	protected static function register(DyeColor $color) : void{
diff --git a/src/block/utils/SkullType.php b/src/block/utils/SkullType.php
index 408d68741..43934ff2d 100644
--- a/src/block/utils/SkullType.php
+++ b/src/block/utils/SkullType.php
@@ -46,15 +46,15 @@ final class SkullType{
 	/** @var SkullType[] */
 	private static $numericIdMap = [];
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new SkullType("skeleton", "Skeleton Skull", 0),
 			new SkullType("wither_skeleton", "Wither Skeleton Skull", 1),
 			new SkullType("zombie", "Zombie Head", 2),
 			new SkullType("player", "Player Head", 3),
 			new SkullType("creeper", "Creeper Head", 4),
 			new SkullType("dragon", "Dragon Head", 5)
-		];
+		);
 	}
 
 	protected static function register(SkullType $type) : void{
diff --git a/src/block/utils/SlabType.php b/src/block/utils/SlabType.php
index 15035637e..a56cf7ed4 100644
--- a/src/block/utils/SlabType.php
+++ b/src/block/utils/SlabType.php
@@ -37,11 +37,11 @@ use pocketmine\utils\EnumTrait;
 final class SlabType{
 	use EnumTrait;
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new self("bottom"),
 			new self("top"),
 			new self("double")
-		];
+		);
 	}
 }
diff --git a/src/block/utils/StairShape.php b/src/block/utils/StairShape.php
index 89f4c544a..b46b19f11 100644
--- a/src/block/utils/StairShape.php
+++ b/src/block/utils/StairShape.php
@@ -39,13 +39,13 @@ use pocketmine\utils\EnumTrait;
 final class StairShape{
 	use EnumTrait;
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new self("straight"),
 			new self("inner_left"),
 			new self("inner_right"),
 			new self("outer_left"),
 			new self("outer_right")
-		];
+		);
 	}
 }
diff --git a/src/block/utils/TreeType.php b/src/block/utils/TreeType.php
index 4d880169a..b3afdd95e 100644
--- a/src/block/utils/TreeType.php
+++ b/src/block/utils/TreeType.php
@@ -46,15 +46,15 @@ final class TreeType{
 	/** @var TreeType[] */
 	private static $numericIdMap = [];
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new TreeType("oak", "Oak", 0),
 			new TreeType("spruce", "Spruce", 1),
 			new TreeType("birch", "Birch", 2),
 			new TreeType("jungle", "Jungle", 3),
 			new TreeType("acacia", "Acacia", 4),
 			new TreeType("dark_oak", "Dark Oak", 5)
-		];
+		);
 	}
 
 	protected static function register(TreeType $type) : void{
diff --git a/src/item/ItemUseResult.php b/src/item/ItemUseResult.php
index 7f8bdba01..446945803 100644
--- a/src/item/ItemUseResult.php
+++ b/src/item/ItemUseResult.php
@@ -37,11 +37,11 @@ use pocketmine\utils\EnumTrait;
 final class ItemUseResult{
 	use EnumTrait;
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new self("none"),
 			new self("fail"),
 			new self("success")
-		];
+		);
 	}
 }
diff --git a/src/item/ToolTier.php b/src/item/ToolTier.php
index 1f2190bb8..30e184e9f 100644
--- a/src/item/ToolTier.php
+++ b/src/item/ToolTier.php
@@ -41,14 +41,14 @@ final class ToolTier{
 		__construct as Enum___construct;
 	}
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new self("wood", 1, 60, 5, 2),
 			new self("gold", 2, 33, 5, 12),
 			new self("stone", 3, 132, 6, 4),
 			new self("iron", 4, 251, 7, 6),
 			new self("diamond", 5, 1562, 8, 8)
-		];
+		);
 	}
 
 	/** @var int */
diff --git a/src/player/GameMode.php b/src/player/GameMode.php
index b4bab2d41..7d95513ba 100644
--- a/src/player/GameMode.php
+++ b/src/player/GameMode.php
@@ -47,13 +47,13 @@ final class GameMode{
 	/** @var self[] */
 	protected static $magicNumberMap = [];
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new self("survival", 0, "Survival", "gameMode.survival", ["s", "0"]),
 			new self("creative", 1, "Creative", "gameMode.creative", ["c", "1"]),
 			new self("adventure", 2, "Adventure", "gameMode.adventure", ["a", "2"]),
 			new self("spectator", 3, "Spectator", "gameMode.spectator", ["v", "view", "3"])
-		];
+		);
 	}
 
 	protected static function register(self $member) : void{
diff --git a/src/plugin/PluginLoadOrder.php b/src/plugin/PluginLoadOrder.php
index 8e27befcf..fa99eeba9 100644
--- a/src/plugin/PluginLoadOrder.php
+++ b/src/plugin/PluginLoadOrder.php
@@ -36,10 +36,10 @@ use pocketmine\utils\EnumTrait;
 final class PluginLoadOrder{
 	use EnumTrait;
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new self("startup"),
 			new self("postworld")
-		];
+		);
 	}
 }
diff --git a/src/utils/EnumTrait.php b/src/utils/EnumTrait.php
index 9092bd888..6f6aa517c 100644
--- a/src/utils/EnumTrait.php
+++ b/src/utils/EnumTrait.php
@@ -38,26 +38,9 @@ trait EnumTrait{
 		self::_registryRegister($member->name(), $member);
 	}
 
-	/**
-	 * Returns an array of enum members to be registered.
-	 *
-	 * (This ought to be private, but traits suck too much for that.)
-	 *
-	 * @return self[]|iterable
-	 */
-	abstract protected static function setup() : iterable;
-
-	/**
-	 * @internal Lazy-inits the enum if necessary.
-	 *
-	 * @throws \InvalidArgumentException
-	 */
-	protected static function checkInit() : void{
-		if(self::$members === null){
-			self::$members = [];
-			foreach(self::setup() as $item){
-				self::register($item);
-			}
+	protected static function registerAll(self ...$members) : void{
+		foreach($members as $member){
+			self::register($member);
 		}
 	}
 
diff --git a/src/world/sound/NoteInstrument.php b/src/world/sound/NoteInstrument.php
index a6fd778f2..cd37df98a 100644
--- a/src/world/sound/NoteInstrument.php
+++ b/src/world/sound/NoteInstrument.php
@@ -41,14 +41,14 @@ final class NoteInstrument{
 		__construct as Enum___construct;
 	}
 
-	protected static function setup() : iterable{
-		return [
+	protected static function setup() : void{
+		self::registerAll(
 			new self("piano", 0),
 			new self("bass_drum", 1),
 			new self("snare", 2),
 			new self("clicks_and_sticks", 3),
 			new self("double_bass", 4)
-		];
+		);
 	}
 
 	/** @var int */