diff --git a/src/pocketmine/Server.php b/src/pocketmine/Server.php
index ac9e10aad..b2c37c22f 100644
--- a/src/pocketmine/Server.php
+++ b/src/pocketmine/Server.php
@@ -728,12 +728,12 @@ class Server{
 		}
 		$spawn = $this->getDefaultLevel()->getSafeSpawn();
 		$nbt = new CompoundTag("", [
-			new LongTag("firstPlayed", floor(microtime(true) * 1000)),
-			new LongTag("lastPlayed", floor(microtime(true) * 1000)),
+			new LongTag("firstPlayed", (int) (microtime(true) * 1000)),
+			new LongTag("lastPlayed", (int) (microtime(true) * 1000)),
 			new ListTag("Pos", [
-				new DoubleTag(0, $spawn->x),
-				new DoubleTag(1, $spawn->y),
-				new DoubleTag(2, $spawn->z)
+				new DoubleTag("", $spawn->x),
+				new DoubleTag("", $spawn->y),
+				new DoubleTag("", $spawn->z)
 			]),
 			new StringTag("Level", $this->getDefaultLevel()->getName()),
 			//new StringTag("SpawnLevel", $this->getDefaultLevel()->getName()),
@@ -745,13 +745,13 @@ class Server{
 			new CompoundTag("Achievements", []),
 			new IntTag("playerGameType", $this->getGamemode()),
 			new ListTag("Motion", [
-				new DoubleTag(0, 0.0),
-				new DoubleTag(1, 0.0),
-				new DoubleTag(2, 0.0)
+				new DoubleTag("", 0.0),
+				new DoubleTag("", 0.0),
+				new DoubleTag("", 0.0)
 			]),
 			new ListTag("Rotation", [
-				new FloatTag(0, 0.0),
-				new FloatTag(1, 0.0)
+				new FloatTag("", 0.0),
+				new FloatTag("", 0.0)
 			]),
 			new FloatTag("FallDistance", 0.0),
 			new ShortTag("Fire", 0),
diff --git a/src/pocketmine/entity/Entity.php b/src/pocketmine/entity/Entity.php
index c18a475b1..cc137bb51 100644
--- a/src/pocketmine/entity/Entity.php
+++ b/src/pocketmine/entity/Entity.php
@@ -738,7 +738,7 @@ abstract class Entity extends Location implements Metadatable{
 			$this->namedtag->id = new StringTag("id", $this->getSaveId());
 			if($this->getNameTag() !== ""){
 				$this->namedtag->CustomName = new StringTag("CustomName", $this->getNameTag());
-				$this->namedtag->CustomNameVisible = new StringTag("CustomNameVisible", $this->isNameTagVisible());
+				$this->namedtag->CustomNameVisible = new ByteTag("CustomNameVisible", $this->isNameTagVisible() ? 1 : 0);
 			}else{
 				unset($this->namedtag->CustomName);
 				unset($this->namedtag->CustomNameVisible);
@@ -746,20 +746,20 @@ abstract class Entity extends Location implements Metadatable{
 		}
 
 		$this->namedtag->Pos = new ListTag("Pos", [
-			new DoubleTag(0, $this->x),
-			new DoubleTag(1, $this->y),
-			new DoubleTag(2, $this->z)
+			new DoubleTag("", $this->x),
+			new DoubleTag("", $this->y),
+			new DoubleTag("", $this->z)
 		]);
 
 		$this->namedtag->Motion = new ListTag("Motion", [
-			new DoubleTag(0, $this->motionX),
-			new DoubleTag(1, $this->motionY),
-			new DoubleTag(2, $this->motionZ)
+			new DoubleTag("", $this->motionX),
+			new DoubleTag("", $this->motionY),
+			new DoubleTag("", $this->motionZ)
 		]);
 
 		$this->namedtag->Rotation = new ListTag("Rotation", [
-			new FloatTag(0, $this->yaw),
-			new FloatTag(1, $this->pitch)
+			new FloatTag("", $this->yaw),
+			new FloatTag("", $this->pitch)
 		]);
 
 		$this->namedtag->FallDistance = new FloatTag("FallDistance", $this->fallDistance);
@@ -771,7 +771,7 @@ abstract class Entity extends Location implements Metadatable{
 		if(count($this->effects) > 0){
 			$effects = [];
 			foreach($this->effects as $effect){
-				$effects[$effect->getId()] = new CompoundTag($effect->getId(), [
+				$effects[] = new CompoundTag("", [
 					"Id" => new ByteTag("Id", $effect->getId()),
 					"Amplifier" => new ByteTag("Amplifier", $effect->getAmplifier()),
 					"Duration" => new IntTag("Duration", $effect->getDuration()),
diff --git a/src/pocketmine/entity/Item.php b/src/pocketmine/entity/Item.php
index 8f3b99a6f..335d43feb 100644
--- a/src/pocketmine/entity/Item.php
+++ b/src/pocketmine/entity/Item.php
@@ -36,8 +36,11 @@ use pocketmine\Player;
 class Item extends Entity{
 	const NETWORK_ID = 64;
 
-	protected $owner = null;
-	protected $thrower = null;
+	/** @var string */
+	protected $owner = "";
+	/** @var string */
+	protected $thrower = "";
+	/** @var int */
 	protected $pickupDelay = 0;
 	/** @var ItemItem */
 	protected $item;
diff --git a/src/pocketmine/entity/Living.php b/src/pocketmine/entity/Living.php
index 5836c40f9..0f4ac8d39 100644
--- a/src/pocketmine/entity/Living.php
+++ b/src/pocketmine/entity/Living.php
@@ -32,6 +32,7 @@ use pocketmine\event\entity\EntityRegainHealthEvent;
 use pocketmine\event\Timings;
 use pocketmine\item\Item as ItemItem;
 use pocketmine\math\Vector3;
+use pocketmine\nbt\tag\FloatTag;
 use pocketmine\nbt\tag\ShortTag;
 use pocketmine\network\mcpe\protocol\EntityEventPacket;
 use pocketmine\utils\BlockIterator;
@@ -51,10 +52,12 @@ abstract class Living extends Entity implements Damageable{
 		parent::initEntity();
 
 		if(isset($this->namedtag->HealF)){
-			$this->namedtag->Health = new ShortTag("Health", (int) $this->namedtag["HealF"]);
+			$this->namedtag->Health = new FloatTag("Health", (float) $this->namedtag["HealF"]);
 			unset($this->namedtag->HealF);
-		}elseif(!isset($this->namedtag->Health) or !($this->namedtag->Health instanceof ShortTag)){
-			$this->namedtag->Health = new ShortTag("Health", $this->getMaxHealth());
+		}elseif(isset($this->namedtag->Health) and !($this->namedtag->Health instanceof FloatTag)){
+			$this->namedtag->Health = new FloatTag("Health", (float) $this->namedtag->Health->getValue());
+		}else{
+			$this->namedtag->Health = new FloatTag("Health", (float) $this->getMaxHealth());
 		}
 
 		$this->setHealth($this->namedtag["Health"]);
diff --git a/src/pocketmine/level/format/io/BaseLevelProvider.php b/src/pocketmine/level/format/io/BaseLevelProvider.php
index 300c84956..dd11bbeb0 100644
--- a/src/pocketmine/level/format/io/BaseLevelProvider.php
+++ b/src/pocketmine/level/format/io/BaseLevelProvider.php
@@ -59,7 +59,7 @@ abstract class BaseLevelProvider implements LevelProvider{
 		}
 
 		if(!isset($this->levelData->generatorName)){
-			$this->levelData->generatorName = new StringTag("generatorName", Generator::getGenerator("DEFAULT"));
+			$this->levelData->generatorName = new StringTag("generatorName", (string) Generator::getGenerator("DEFAULT"));
 		}
 
 		if(!isset($this->levelData->generatorOptions)){
diff --git a/src/pocketmine/level/format/io/leveldb/LevelDB.php b/src/pocketmine/level/format/io/leveldb/LevelDB.php
index b08ee7a01..79b782dbf 100644
--- a/src/pocketmine/level/format/io/leveldb/LevelDB.php
+++ b/src/pocketmine/level/format/io/leveldb/LevelDB.php
@@ -95,7 +95,7 @@ class LevelDB extends BaseLevelProvider{
 			if(isset($this->levelData->Generator)){
 				switch((int) $this->levelData->Generator->getValue()){ //Detect correct generator from MCPE data
 					case self::GENERATOR_FLAT:
-						$this->levelData->generatorName = new StringTag("generatorName", Generator::getGenerator("FLAT"));
+						$this->levelData->generatorName = new StringTag("generatorName", (string) Generator::getGenerator("FLAT"));
 						if(($layers = $this->db->get(self::ENTRY_FLAT_WORLD_LAYERS)) !== false){ //Detect existing custom flat layers
 							$layers = trim($layers, "[]");
 						}else{
@@ -105,7 +105,7 @@ class LevelDB extends BaseLevelProvider{
 						break;
 					case self::GENERATOR_INFINITE:
 						//TODO: add a null generator which does not generate missing chunks (to allow importing back to MCPE and generating more normal terrain without PocketMine messing things up)
-						$this->levelData->generatorName = new StringTag("generatorName", Generator::getGenerator("DEFAULT"));
+						$this->levelData->generatorName = new StringTag("generatorName", (string) Generator::getGenerator("DEFAULT"));
 						$this->levelData->generatorOptions = new StringTag("generatorOptions", "");
 						break;
 					case self::GENERATOR_LIMITED:
@@ -114,7 +114,7 @@ class LevelDB extends BaseLevelProvider{
 						throw new LevelException("Unknown LevelDB world format type, this level cannot be loaded");
 				}
 			}else{
-				$this->levelData->generatorName = new StringTag("generatorName", Generator::getGenerator("DEFAULT"));
+				$this->levelData->generatorName = new StringTag("generatorName", (string) Generator::getGenerator("DEFAULT"));
 			}
 		}
 
diff --git a/src/pocketmine/level/format/io/region/Anvil.php b/src/pocketmine/level/format/io/region/Anvil.php
index 163712cde..7e35da205 100644
--- a/src/pocketmine/level/format/io/region/Anvil.php
+++ b/src/pocketmine/level/format/io/region/Anvil.php
@@ -56,7 +56,7 @@ class Anvil extends McRegion{
 			if($subChunk->isEmpty()){
 				continue;
 			}
-			$nbt->Sections[++$subChunks] = new CompoundTag(null, [
+			$nbt->Sections[++$subChunks] = new CompoundTag("", [
 				"Y"          => new ByteTag("Y", $y),
 				"Blocks"     => new ByteArrayTag("Blocks", ChunkUtils::reorderByteArray($subChunk->getBlockIdArray())), //Generic in-memory chunks are currently always XZY
 				"Data"       => new ByteArrayTag("Data", ChunkUtils::reorderNibbleArray($subChunk->getBlockDataArray())),
diff --git a/src/pocketmine/level/format/io/region/PMAnvil.php b/src/pocketmine/level/format/io/region/PMAnvil.php
index 3a165a188..c3b8c590e 100644
--- a/src/pocketmine/level/format/io/region/PMAnvil.php
+++ b/src/pocketmine/level/format/io/region/PMAnvil.php
@@ -59,7 +59,7 @@ class PMAnvil extends Anvil{
 			if($subChunk->isEmpty()){
 				continue;
 			}
-			$nbt->Sections[++$subChunks] = new CompoundTag(null, [
+			$nbt->Sections[++$subChunks] = new CompoundTag("", [
 				"Y"          => new ByteTag("Y", $y),
 				"Blocks"     => new ByteArrayTag("Blocks",     $subChunk->getBlockIdArray()),
 				"Data"       => new ByteArrayTag("Data",       $subChunk->getBlockDataArray()),
diff --git a/src/pocketmine/nbt/tag/ByteArrayTag.php b/src/pocketmine/nbt/tag/ByteArrayTag.php
index 00bc696c0..75eb3e71a 100644
--- a/src/pocketmine/nbt/tag/ByteArrayTag.php
+++ b/src/pocketmine/nbt/tag/ByteArrayTag.php
@@ -29,6 +29,16 @@ use pocketmine\nbt\NBT;
 
 class ByteArrayTag extends NamedTag{
 
+	/**
+	 * ByteArrayTag constructor.
+	 *
+	 * @param string $name
+	 * @param string $value
+	 */
+	public function __construct(string $name = "", string $value = ""){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_ByteArray;
 	}
@@ -41,4 +51,23 @@ class ByteArrayTag extends NamedTag{
 		$nbt->putInt(strlen($this->value), $network);
 		$nbt->put($this->value);
 	}
+
+	/**
+	 * @return string
+	 */
+	public function &getValue() : string{
+		return parent::getValue(); // TODO: Change the autogenerated stub
+	}
+
+	/**
+	 * @param string $value
+	 *
+	 * @throws \TypeError
+	 */
+	public function setValue($value){
+		if(!is_string($value)){
+			throw new \TypeError("ByteArrayTag value must be of type string, " . gettype($value) . " given");
+		}
+		parent::setValue($value);
+	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/nbt/tag/ByteTag.php b/src/pocketmine/nbt/tag/ByteTag.php
index 3aa13b512..6a5c9311f 100644
--- a/src/pocketmine/nbt/tag/ByteTag.php
+++ b/src/pocketmine/nbt/tag/ByteTag.php
@@ -29,6 +29,16 @@ use pocketmine\nbt\NBT;
 
 class ByteTag extends NamedTag{
 
+	/**
+	 * ByteTag constructor.
+	 *
+	 * @param string $name
+	 * @param int    $value
+	 */
+	public function __construct(string $name = "", int $value = 0){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_Byte;
 	}
@@ -40,4 +50,25 @@ class ByteTag extends NamedTag{
 	public function write(NBT $nbt, bool $network = false){
 		$nbt->putByte($this->value);
 	}
+
+	/**
+	 * @return int
+	 */
+	public function &getValue() : int{
+		return parent::getValue();
+	}
+
+	/**
+	 * @param int $value
+	 *
+	 * @throws \TypeError
+	 */
+	public function setValue($value){
+		if(!is_int($value)){
+			throw new \TypeError("ByteTag value must be of type int, " . gettype($value) . " given");
+		}elseif($value < -(2 ** 7) or $value > ((2 ** 7) - 1)){
+			throw new \InvalidArgumentException("Value $value is too large!");
+		}
+		parent::setValue($value);
+	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/nbt/tag/CompoundTag.php b/src/pocketmine/nbt/tag/CompoundTag.php
index 623b00e0a..e7413494f 100644
--- a/src/pocketmine/nbt/tag/CompoundTag.php
+++ b/src/pocketmine/nbt/tag/CompoundTag.php
@@ -30,14 +30,13 @@ use pocketmine\nbt\NBT;
 class CompoundTag extends NamedTag implements \ArrayAccess{
 
 	/**
+	 * CompoundTag constructor.
+	 *
 	 * @param string     $name
 	 * @param NamedTag[] $value
 	 */
-	public function __construct($name = "", $value = []){
-		$this->__name = $name;
-		foreach($value as $tag){
-			$this->{$tag->getName()} = $tag;
-		}
+	public function __construct(string $name = "", array $value = []){
+		parent::__construct($name, $value);
 	}
 
 	public function getCount(){
@@ -51,13 +50,22 @@ class CompoundTag extends NamedTag implements \ArrayAccess{
 		return $count;
 	}
 
+	/**
+	 * @param NamedTag[] $value
+	 *
+	 * @throws \TypeError
+	 */
 	public function setValue($value){
 		if(is_array($value)){
 			foreach($value as $name => $tag){
 				if($tag instanceof NamedTag){
-					$this->{$name} = $tag;
+					$this->{$tag->getName()} = $tag;
+				}else{
+					throw new \TypeError("CompoundTag members must be NamedTags, got " . gettype($tag) . " in given array");
 				}
 			}
+		}else{
+			throw new \TypeError("CompoundTag value must be NamedTag[], " . gettype($value) . " given");
 		}
 	}
 
diff --git a/src/pocketmine/nbt/tag/DoubleTag.php b/src/pocketmine/nbt/tag/DoubleTag.php
index f0eb71f63..e60647daf 100644
--- a/src/pocketmine/nbt/tag/DoubleTag.php
+++ b/src/pocketmine/nbt/tag/DoubleTag.php
@@ -29,6 +29,16 @@ use pocketmine\nbt\NBT;
 
 class DoubleTag extends NamedTag{
 
+	/**
+	 * DoubleTag constructor.
+	 *
+	 * @param string $name
+	 * @param float  $value
+	 */
+	public function __construct(string $name = "", float $value = 0.0){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_Double;
 	}
@@ -40,4 +50,23 @@ class DoubleTag extends NamedTag{
 	public function write(NBT $nbt, bool $network = false){
 		$nbt->putDouble($this->value);
 	}
+
+	/**
+	 * @return float
+	 */
+	public function &getValue() : float{
+		return parent::getValue();
+	}
+
+	/**
+	 * @param float $value
+	 *
+	 * @throws \TypeError
+	 */
+	public function setValue($value){
+		if(!is_float($value) and !is_int($value)){
+			throw new \TypeError("DoubleTag value must be of type double, " . gettype($value) . " given");
+		}
+		parent::setValue((float) $value);
+	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/nbt/tag/FloatTag.php b/src/pocketmine/nbt/tag/FloatTag.php
index 2201aa427..b0cea1fb3 100644
--- a/src/pocketmine/nbt/tag/FloatTag.php
+++ b/src/pocketmine/nbt/tag/FloatTag.php
@@ -29,6 +29,16 @@ use pocketmine\nbt\NBT;
 
 class FloatTag extends NamedTag{
 
+	/**
+	 * FloatTag constructor.
+	 *
+	 * @param string $name
+	 * @param float  $value
+	 */
+	public function __construct(string $name = "", float $value = 0.0){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_Float;
 	}
@@ -40,4 +50,18 @@ class FloatTag extends NamedTag{
 	public function write(NBT $nbt, bool $network = false){
 		$nbt->putFloat($this->value);
 	}
+
+	/**
+	 * @return float
+	 */
+	public function &getValue() : float{
+		return parent::getValue();
+	}
+
+	public function setValue($value){
+		if(!is_float($value) and !is_int($value)){
+			throw new \TypeError("FloatTag value must be of type float, " . gettype($value) . " given");
+		}
+		parent::setValue((float) $value);
+	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/nbt/tag/IntArrayTag.php b/src/pocketmine/nbt/tag/IntArrayTag.php
index 1a507e777..f409f7fb6 100644
--- a/src/pocketmine/nbt/tag/IntArrayTag.php
+++ b/src/pocketmine/nbt/tag/IntArrayTag.php
@@ -29,6 +29,16 @@ use pocketmine\nbt\NBT;
 
 class IntArrayTag extends NamedTag{
 
+	/**
+	 * IntArrayTag constructor.
+	 *
+	 * @param string $name
+	 * @param int[]  $value
+	 */
+	public function __construct(string $name = "", array $value = []){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_IntArray;
 	}
@@ -48,4 +58,27 @@ class IntArrayTag extends NamedTag{
 		$str .= implode(", ", $this->value);
 		return $str . "}";
 	}
+
+	/**
+	 * @return int[]
+	 */
+	public function &getValue() : array{
+		return parent::getValue();
+	}
+
+	/**
+	 * @param int[] $value
+	 *
+	 * @throws \TypeError
+	 */
+	public function setValue($value){
+		if(!is_array($value)){
+			throw new \TypeError("IntArrayTag value must be of type int[], " . gettype($value) . " given");
+		}
+		assert(count(array_filter($value, function($v){
+			return !is_int($v);
+		})) === 0);
+
+		parent::setValue($value);
+	}
 }
diff --git a/src/pocketmine/nbt/tag/IntTag.php b/src/pocketmine/nbt/tag/IntTag.php
index 77580f9c0..990433808 100644
--- a/src/pocketmine/nbt/tag/IntTag.php
+++ b/src/pocketmine/nbt/tag/IntTag.php
@@ -29,6 +29,14 @@ use pocketmine\nbt\NBT;
 
 class IntTag extends NamedTag{
 
+	/**
+	 * @param string $name
+	 * @param int    $value
+	 */
+	public function __construct(string $name = "", int $value = 0){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_Int;
 	}
@@ -40,4 +48,25 @@ class IntTag extends NamedTag{
 	public function write(NBT $nbt, bool $network = false){
 		$nbt->putInt($this->value, $network);
 	}
+
+	/**
+	 * @return int
+	 */
+	public function &getValue() : int{
+		return parent::getValue();
+	}
+
+	/**
+	 * @param int $value
+	 *
+	 * @throws \TypeError
+	 */
+	public function setValue($value){
+		if(!is_int($value)){
+			throw new \TypeError("IntTag value must be of type int, " . gettype($value) . " given");
+		}elseif($value < -(2 ** 31) or $value > ((2 ** 31) - 1)){
+			throw new \InvalidArgumentException("Value $value is too large!");
+		}
+		parent::setValue($value);
+	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/nbt/tag/ListTag.php b/src/pocketmine/nbt/tag/ListTag.php
index 23197dbd1..ac6d709fd 100644
--- a/src/pocketmine/nbt/tag/ListTag.php
+++ b/src/pocketmine/nbt/tag/ListTag.php
@@ -31,14 +31,20 @@ class ListTag extends NamedTag implements \ArrayAccess, \Countable{
 
 	private $tagType = NBT::TAG_End;
 
-	public function __construct($name = "", $value = []){
-		$this->__name = $name;
-		foreach($value as $k => $v){
-			$this->{$k} = $v;
-		}
+	/**
+	 * ListTag constructor.
+	 *
+	 * @param string     $name
+	 * @param NamedTag[] $value
+	 */
+	public function __construct(string $name = "", array $value = []){
+		parent::__construct($name, $value);
 	}
 
-	public function &getValue(){
+	/**
+	 * @return NamedTag[]
+	 */
+	public function &getValue() : array{
 		$value = [];
 		foreach($this as $k => $v){
 			if($v instanceof Tag){
@@ -49,13 +55,22 @@ class ListTag extends NamedTag implements \ArrayAccess, \Countable{
 		return $value;
 	}
 
+	/**
+	 * @param NamedTag[] $value
+	 *
+	 * @throws \TypeError
+	 */
 	public function setValue($value){
 		if(is_array($value)){
 			foreach($value as $name => $tag){
 				if($tag instanceof NamedTag){
 					$this->{$name} = $tag;
+				}else{
+					throw new \TypeError("ListTag members must be NamedTags, got " . gettype($tag) . " in given array");
 				}
 			}
+		}else{
+			throw new \TypeError("ListTag value must be NamedTag[], " . gettype($value) . " given");
 		}
 	}
 
diff --git a/src/pocketmine/nbt/tag/LongTag.php b/src/pocketmine/nbt/tag/LongTag.php
index d5b907289..867e07077 100644
--- a/src/pocketmine/nbt/tag/LongTag.php
+++ b/src/pocketmine/nbt/tag/LongTag.php
@@ -29,6 +29,16 @@ use pocketmine\nbt\NBT;
 
 class LongTag extends NamedTag{
 
+	/**
+	 * LongTag constructor.
+	 *
+	 * @param string $name
+	 * @param int    $value
+	 */
+	public function __construct(string $name = "", int $value = 0){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_Long;
 	}
diff --git a/src/pocketmine/nbt/tag/NamedTag.php b/src/pocketmine/nbt/tag/NamedTag.php
index b7d29774c..745bbe1e2 100644
--- a/src/pocketmine/nbt/tag/NamedTag.php
+++ b/src/pocketmine/nbt/tag/NamedTag.php
@@ -29,13 +29,13 @@ abstract class NamedTag extends Tag{
 	protected $__name;
 
 	/**
-	 * @param string                                                                  $name
-	 * @param bool|float|double|int|ByteTag|ShortTag|array|CompoundTag|ListTag|string $value
+	 * @param string $name
+	 * @param mixed  $value
 	 */
-	public function __construct($name = "", $value = null){
+	public function __construct(string $name = "", $value = null){
 		$this->__name = ($name === null or $name === false) ? "" : $name;
 		if($value !== null){
-			$this->value = $value;
+			$this->setValue($value);
 		}
 	}
 
diff --git a/src/pocketmine/nbt/tag/ShortTag.php b/src/pocketmine/nbt/tag/ShortTag.php
index 707907de2..9317f0a98 100644
--- a/src/pocketmine/nbt/tag/ShortTag.php
+++ b/src/pocketmine/nbt/tag/ShortTag.php
@@ -29,6 +29,16 @@ use pocketmine\nbt\NBT;
 
 class ShortTag extends NamedTag{
 
+	/**
+	 * ShortTag constructor.
+	 *
+	 * @param string $name
+	 * @param int    $value
+	 */
+	public function __construct(string $name = "", int $value = 0){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_Short;
 	}
@@ -40,4 +50,25 @@ class ShortTag extends NamedTag{
 	public function write(NBT $nbt, bool $network = false){
 		$nbt->putShort($this->value);
 	}
+
+	/**
+	 * @return int
+	 */
+	public function &getValue() : int{
+		return parent::getValue(); // TODO: Change the autogenerated stub
+	}
+
+	/**
+	 * @param int $value
+	 *
+	 * @throws \TypeError
+	 */
+	public function setValue($value){
+		if(!is_int($value)){
+			throw new \TypeError("ShortTag value must be of type int, " . gettype($value) . " given");
+		}elseif($value < -(2 ** 15) or $value > ((2 ** 15) - 1)){
+			throw new \InvalidArgumentException("Value $value is too large!");
+		}
+		parent::setValue($value);
+	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/nbt/tag/StringTag.php b/src/pocketmine/nbt/tag/StringTag.php
index d44b440e8..1f3e1c41b 100644
--- a/src/pocketmine/nbt/tag/StringTag.php
+++ b/src/pocketmine/nbt/tag/StringTag.php
@@ -29,6 +29,16 @@ use pocketmine\nbt\NBT;
 
 class StringTag extends NamedTag{
 
+	/**
+	 * StringTag constructor.
+	 *
+	 * @param string $name
+	 * @param string $value
+	 */
+	public function __construct(string $name = "", string $value = ""){
+		parent::__construct($name, $value);
+	}
+
 	public function getType(){
 		return NBT::TAG_String;
 	}
@@ -40,4 +50,23 @@ class StringTag extends NamedTag{
 	public function write(NBT $nbt, bool $network = false){
 		$nbt->putString($this->value, $network);
 	}
+
+	/**
+	 * @return string
+	 */
+	public function &getValue() : string{
+		return parent::getValue();
+	}
+
+	/**
+	 * @param string $value
+	 *
+	 * @throws \TypeError
+	 */
+	public function setValue($value){
+		if(!is_string($value)){
+			throw new \TypeError("ShortTag value must be of type int, " . gettype($value) . " given");
+		}
+		parent::setValue($value);
+	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/tile/Chest.php b/src/pocketmine/tile/Chest.php
index 708c3b789..c3df50689 100644
--- a/src/pocketmine/tile/Chest.php
+++ b/src/pocketmine/tile/Chest.php
@@ -190,15 +190,24 @@ class Chest extends Spawnable implements InventoryHolder, Container, Nameable{
 		}
 	}
 
-	public function getName(){
+	/**
+	 * @return string
+	 */
+	public function getName() : string{
 		return isset($this->namedtag->CustomName) ? $this->namedtag->CustomName->getValue() : "Chest";
 	}
 
-	public function hasName(){
+	/**
+	 * @return bool
+	 */
+	public function hasName() : bool{
 		return isset($this->namedtag->CustomName);
 	}
 
-	public function setName($str){
+	/**
+	 * @param string $str
+	 */
+	public function setName(string $str){
 		if($str === ""){
 			unset($this->namedtag->CustomName);
 			return;
diff --git a/src/pocketmine/tile/EnchantTable.php b/src/pocketmine/tile/EnchantTable.php
index d6ff0ba32..aa16bd4a4 100644
--- a/src/pocketmine/tile/EnchantTable.php
+++ b/src/pocketmine/tile/EnchantTable.php
@@ -30,15 +30,15 @@ use pocketmine\nbt\tag\StringTag;
 class EnchantTable extends Spawnable implements Nameable{
 
 
-	public function getName(){
+	public function getName() : string{
 		return isset($this->namedtag->CustomName) ? $this->namedtag->CustomName->getValue() : "Enchanting Table";
 	}
 
-	public function hasName(){
+	public function hasName() : bool{
 		return isset($this->namedtag->CustomName);
 	}
 
-	public function setName($str){
+	public function setName(string $str){
 		if($str === ""){
 			unset($this->namedtag->CustomName);
 			return;
diff --git a/src/pocketmine/tile/Furnace.php b/src/pocketmine/tile/Furnace.php
index e960e73d8..574df3d27 100644
--- a/src/pocketmine/tile/Furnace.php
+++ b/src/pocketmine/tile/Furnace.php
@@ -72,15 +72,15 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 		}
 	}
 
-	public function getName(){
+	public function getName() : string{
 		return isset($this->namedtag->CustomName) ? $this->namedtag->CustomName->getValue() : "Furnace";
 	}
 
-	public function hasName(){
+	public function hasName() : bool{
 		return isset($this->namedtag->CustomName);
 	}
 
-	public function setName($str){
+	public function setName(string $str){
 		if($str === ""){
 			unset($this->namedtag->CustomName);
 			return;
@@ -228,11 +228,11 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 		}
 
 		if($this->namedtag["BurnTime"] > 0){
-			$this->namedtag->BurnTime = new ShortTag("BurnTime", $this->namedtag["BurnTime"] - 1);
+			$this->namedtag->BurnTime = new ShortTag("BurnTime", ((int) $this->namedtag["BurnTime"]) - 1);
 			$this->namedtag->BurnTicks = new ShortTag("BurnTicks", (int) ceil(($this->namedtag["BurnTime"] / $this->namedtag["MaxTime"] * 200)));
 
 			if($smelt instanceof FurnaceRecipe and $canSmelt){
-				$this->namedtag->CookTime = new ShortTag("CookTime", $this->namedtag["CookTime"] + 1);
+				$this->namedtag->CookTime = new ShortTag("CookTime", (int) ($this->namedtag["CookTime"]) + 1);
 				if($this->namedtag["CookTime"] >= 200){ //10 seconds
 					$product = Item::get($smelt->getResult()->getId(), $smelt->getResult()->getDamage(), $product->getCount() + 1);
 
@@ -247,7 +247,7 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 						$this->inventory->setSmelting($raw);
 					}
 
-					$this->namedtag->CookTime = new ShortTag("CookTime", $this->namedtag["CookTime"] - 200);
+					$this->namedtag->CookTime = new ShortTag("CookTime", ((int) $this->namedtag["CookTime"]) - 200);
 				}
 			}elseif($this->namedtag["BurnTime"] <= 0){
 				$this->namedtag->BurnTime = new ShortTag("BurnTime", 0);
@@ -297,8 +297,8 @@ class Furnace extends Spawnable implements InventoryHolder, Container, Nameable{
 			new IntTag("x", (int) $this->x),
 			new IntTag("y", (int) $this->y),
 			new IntTag("z", (int) $this->z),
-			new ShortTag("BurnTime", $this->namedtag["BurnTime"]),
-			new ShortTag("CookTime", $this->namedtag["CookTime"])
+			new ShortTag("BurnTime", (int) $this->namedtag["BurnTime"]),
+			new ShortTag("CookTime", (int) $this->namedtag["CookTime"])
 		]);
 
 		if($this->hasName()){
diff --git a/src/pocketmine/tile/Nameable.php b/src/pocketmine/tile/Nameable.php
index 6651c927d..43a1a9154 100644
--- a/src/pocketmine/tile/Nameable.php
+++ b/src/pocketmine/tile/Nameable.php
@@ -30,15 +30,15 @@ interface Nameable{
 	/**
 	 * @return string
 	 */
-	public function getName();
+	public function getName() : string;
 
 	/**
-	 * @param void $str
+	 * @param string $str
 	 */
-	public function setName($str);
+	public function setName(string $str);
 
 	/**
 	 * @return bool
 	 */
-	public function hasName();
+	public function hasName() : bool;
 }