diff --git a/src/pocketmine/nbt/tag/ByteArrayTag.php b/src/pocketmine/nbt/tag/ByteArrayTag.php
index 1a92a23c5..641a490ef 100644
--- a/src/pocketmine/nbt/tag/ByteArrayTag.php
+++ b/src/pocketmine/nbt/tag/ByteArrayTag.php
@@ -39,15 +39,15 @@ class ByteArrayTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_ByteArray;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = $nbt->get($nbt->getInt($network));
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putInt(strlen($this->value), $network);
 		$nbt->put($this->value);
 	}
@@ -64,7 +64,7 @@ class ByteArrayTag extends NamedTag{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(!is_string($value)){
 			throw new \TypeError("ByteArrayTag value must be of type string, " . gettype($value) . " given");
 		}
diff --git a/src/pocketmine/nbt/tag/ByteTag.php b/src/pocketmine/nbt/tag/ByteTag.php
index 6a5c9311f..21cc6c213 100644
--- a/src/pocketmine/nbt/tag/ByteTag.php
+++ b/src/pocketmine/nbt/tag/ByteTag.php
@@ -39,15 +39,15 @@ class ByteTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_Byte;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = $nbt->getSignedByte();
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putByte($this->value);
 	}
 
@@ -63,7 +63,7 @@ class ByteTag extends NamedTag{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(!is_int($value)){
 			throw new \TypeError("ByteTag value must be of type int, " . gettype($value) . " given");
 		}elseif($value < -(2 ** 7) or $value > ((2 ** 7) - 1)){
diff --git a/src/pocketmine/nbt/tag/CompoundTag.php b/src/pocketmine/nbt/tag/CompoundTag.php
index 844213e35..1e83cafe7 100644
--- a/src/pocketmine/nbt/tag/CompoundTag.php
+++ b/src/pocketmine/nbt/tag/CompoundTag.php
@@ -55,7 +55,7 @@ class CompoundTag extends NamedTag implements \ArrayAccess{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(is_array($value)){
 			foreach($value as $name => $tag){
 				if($tag instanceof NamedTag){
@@ -385,11 +385,11 @@ class CompoundTag extends NamedTag implements \ArrayAccess{
 		unset($this->{$offset});
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_Compound;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = [];
 		do{
 			$tag = $nbt->readTag($network);
@@ -399,7 +399,7 @@ class CompoundTag extends NamedTag implements \ArrayAccess{
 		}while(!($tag instanceof EndTag) and !$nbt->feof());
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		foreach($this as $tag){
 			if($tag instanceof Tag and !($tag instanceof EndTag)){
 				$nbt->writeTag($tag, $network);
diff --git a/src/pocketmine/nbt/tag/DoubleTag.php b/src/pocketmine/nbt/tag/DoubleTag.php
index e60647daf..7fa31e5d9 100644
--- a/src/pocketmine/nbt/tag/DoubleTag.php
+++ b/src/pocketmine/nbt/tag/DoubleTag.php
@@ -39,15 +39,15 @@ class DoubleTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_Double;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = $nbt->getDouble();
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putDouble($this->value);
 	}
 
@@ -63,7 +63,7 @@ class DoubleTag extends NamedTag{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(!is_float($value) and !is_int($value)){
 			throw new \TypeError("DoubleTag value must be of type double, " . gettype($value) . " given");
 		}
diff --git a/src/pocketmine/nbt/tag/EndTag.php b/src/pocketmine/nbt/tag/EndTag.php
index 19ea1e558..3fca03005 100644
--- a/src/pocketmine/nbt/tag/EndTag.php
+++ b/src/pocketmine/nbt/tag/EndTag.php
@@ -27,15 +27,15 @@ use pocketmine\nbt\NBT;
 
 class EndTag extends Tag{
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_End;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 
 	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/nbt/tag/FloatTag.php b/src/pocketmine/nbt/tag/FloatTag.php
index b0cea1fb3..9923f4fec 100644
--- a/src/pocketmine/nbt/tag/FloatTag.php
+++ b/src/pocketmine/nbt/tag/FloatTag.php
@@ -39,15 +39,15 @@ class FloatTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_Float;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = $nbt->getFloat();
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putFloat($this->value);
 	}
 
@@ -58,7 +58,7 @@ class FloatTag extends NamedTag{
 		return parent::getValue();
 	}
 
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(!is_float($value) and !is_int($value)){
 			throw new \TypeError("FloatTag value must be of type float, " . gettype($value) . " given");
 		}
diff --git a/src/pocketmine/nbt/tag/IntArrayTag.php b/src/pocketmine/nbt/tag/IntArrayTag.php
index f409f7fb6..bb1c9e8ea 100644
--- a/src/pocketmine/nbt/tag/IntArrayTag.php
+++ b/src/pocketmine/nbt/tag/IntArrayTag.php
@@ -39,16 +39,16 @@ class IntArrayTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_IntArray;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$size = $nbt->getInt($network);
 		$this->value = array_values(unpack($nbt->endianness === NBT::LITTLE_ENDIAN ? "V*" : "N*", $nbt->get($size * 4)));
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putInt(count($this->value), $network);
 		$nbt->put(pack($nbt->endianness === NBT::LITTLE_ENDIAN ? "V*" : "N*", ...$this->value));
 	}
@@ -71,7 +71,7 @@ class IntArrayTag extends NamedTag{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(!is_array($value)){
 			throw new \TypeError("IntArrayTag value must be of type int[], " . gettype($value) . " given");
 		}
diff --git a/src/pocketmine/nbt/tag/IntTag.php b/src/pocketmine/nbt/tag/IntTag.php
index 990433808..da4e555db 100644
--- a/src/pocketmine/nbt/tag/IntTag.php
+++ b/src/pocketmine/nbt/tag/IntTag.php
@@ -37,15 +37,15 @@ class IntTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_Int;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = $nbt->getInt($network);
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putInt($this->value, $network);
 	}
 
@@ -61,7 +61,7 @@ class IntTag extends NamedTag{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(!is_int($value)){
 			throw new \TypeError("IntTag value must be of type int, " . gettype($value) . " given");
 		}elseif($value < -(2 ** 31) or $value > ((2 ** 31) - 1)){
diff --git a/src/pocketmine/nbt/tag/ListTag.php b/src/pocketmine/nbt/tag/ListTag.php
index c03fb0f7c..bb0501ce5 100644
--- a/src/pocketmine/nbt/tag/ListTag.php
+++ b/src/pocketmine/nbt/tag/ListTag.php
@@ -63,7 +63,7 @@ class ListTag extends NamedTag implements \ArrayAccess, \Countable{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(is_array($value)){
 			foreach($value as $name => $tag){
 				if($tag instanceof NamedTag){
@@ -129,7 +129,7 @@ class ListTag extends NamedTag implements \ArrayAccess, \Countable{
 		return $count;
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_List;
 	}
 
@@ -141,7 +141,7 @@ class ListTag extends NamedTag implements \ArrayAccess, \Countable{
 		return $this->tagType;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = [];
 		$this->tagType = $nbt->getByte();
 		$size = $nbt->getInt($network);
@@ -154,7 +154,7 @@ class ListTag extends NamedTag implements \ArrayAccess, \Countable{
 		}
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		if($this->tagType === NBT::TAG_End){ //previously empty list, try detecting type from tag children
 			$id = NBT::TAG_End;
 			foreach($this as $tag){
@@ -162,7 +162,7 @@ class ListTag extends NamedTag implements \ArrayAccess, \Countable{
 					if($id === NBT::TAG_End){
 						$id = $tag->getType();
 					}elseif($id !== $tag->getType()){
-						return false;
+						return; //TODO: throw exception?
 					}
 				}
 			}
@@ -182,8 +182,6 @@ class ListTag extends NamedTag implements \ArrayAccess, \Countable{
 		foreach($tags as $tag){
 			$tag->write($nbt, $network);
 		}
-
-		return true;
 	}
 
 	public function __toString(){
diff --git a/src/pocketmine/nbt/tag/LongTag.php b/src/pocketmine/nbt/tag/LongTag.php
index c10d05e3d..fe1e1fff2 100644
--- a/src/pocketmine/nbt/tag/LongTag.php
+++ b/src/pocketmine/nbt/tag/LongTag.php
@@ -39,15 +39,15 @@ class LongTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_Long;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = $nbt->getLong($network);
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putLong($this->value, $network);
 	}
 
diff --git a/src/pocketmine/nbt/tag/NamedTag.php b/src/pocketmine/nbt/tag/NamedTag.php
index 745bbe1e2..4e5cda766 100644
--- a/src/pocketmine/nbt/tag/NamedTag.php
+++ b/src/pocketmine/nbt/tag/NamedTag.php
@@ -25,7 +25,7 @@ namespace pocketmine\nbt\tag;
 
 
 abstract class NamedTag extends Tag{
-
+	/** @var string */
 	protected $__name;
 
 	/**
@@ -39,11 +39,17 @@ abstract class NamedTag extends Tag{
 		}
 	}
 
-	public function getName(){
+	/**
+	 * @return string
+	 */
+	public function getName() : string{
 		return $this->__name;
 	}
 
-	public function setName($name){
+	/**
+	 * @param string $name
+	 */
+	public function setName(string $name) : void{
 		$this->__name = $name;
 	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/nbt/tag/ShortTag.php b/src/pocketmine/nbt/tag/ShortTag.php
index 2c833e804..70338fbad 100644
--- a/src/pocketmine/nbt/tag/ShortTag.php
+++ b/src/pocketmine/nbt/tag/ShortTag.php
@@ -39,15 +39,15 @@ class ShortTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_Short;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = $nbt->getSignedShort();
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putShort($this->value);
 	}
 
@@ -63,7 +63,7 @@ class ShortTag extends NamedTag{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(!is_int($value)){
 			throw new \TypeError("ShortTag value must be of type int, " . gettype($value) . " given");
 		}elseif($value < -(2 ** 15) or $value > ((2 ** 15) - 1)){
diff --git a/src/pocketmine/nbt/tag/StringTag.php b/src/pocketmine/nbt/tag/StringTag.php
index 1f3e1c41b..8ed19757a 100644
--- a/src/pocketmine/nbt/tag/StringTag.php
+++ b/src/pocketmine/nbt/tag/StringTag.php
@@ -39,15 +39,15 @@ class StringTag extends NamedTag{
 		parent::__construct($name, $value);
 	}
 
-	public function getType(){
+	public function getType() : int{
 		return NBT::TAG_String;
 	}
 
-	public function read(NBT $nbt, bool $network = false){
+	public function read(NBT $nbt, bool $network = false) : void{
 		$this->value = $nbt->getString($network);
 	}
 
-	public function write(NBT $nbt, bool $network = false){
+	public function write(NBT $nbt, bool $network = false) : void{
 		$nbt->putString($this->value, $network);
 	}
 
@@ -63,7 +63,7 @@ class StringTag extends NamedTag{
 	 *
 	 * @throws \TypeError
 	 */
-	public function setValue($value){
+	public function setValue($value) : void{
 		if(!is_string($value)){
 			throw new \TypeError("ShortTag value must be of type int, " . gettype($value) . " given");
 		}
diff --git a/src/pocketmine/nbt/tag/Tag.php b/src/pocketmine/nbt/tag/Tag.php
index 849b43ffc..74e4d7b78 100644
--- a/src/pocketmine/nbt/tag/Tag.php
+++ b/src/pocketmine/nbt/tag/Tag.php
@@ -36,15 +36,15 @@ abstract class Tag extends \stdClass{
 		return $this->value;
 	}
 
-	abstract public function getType();
+	abstract public function getType() : int;
 
-	public function setValue($value){
+	public function setValue($value) : void{
 		$this->value = $value;
 	}
 
-	abstract public function write(NBT $nbt, bool $network = false);
+	abstract public function write(NBT $nbt, bool $network = false) : void;
 
-	abstract public function read(NBT $nbt, bool $network = false);
+	abstract public function read(NBT $nbt, bool $network = false) : void;
 
 	public function __toString(){
 		return (string) $this->value;