diff --git a/src/pocketmine/level/format/generic/EmptySubChunk.php b/src/pocketmine/level/format/generic/EmptySubChunk.php
index e810b8771..a7a5e702b 100644
--- a/src/pocketmine/level/format/generic/EmptySubChunk.php
+++ b/src/pocketmine/level/format/generic/EmptySubChunk.php
@@ -59,14 +59,6 @@ class EmptySubChunk extends SubChunk{
 		return false;
 	}
 
-	public function getBlockSkyLight(int $x, int $y, int $z) : int{
-		return 15;
-	}
-
-	public function setBlockSkyLight(int $x, int $y, int $z, int $level) : bool{
-		return false;
-	}
-
 	public function getBlockLight(int $x, int $y, int $z) : int{
 		return 0;
 	}
@@ -75,6 +67,14 @@ class EmptySubChunk extends SubChunk{
 		return false;
 	}
 
+	public function getBlockSkyLight(int $x, int $y, int $z) : int{
+		return 15;
+	}
+
+	public function setBlockSkyLight(int $x, int $y, int $z, int $level) : bool{
+		return false;
+	}
+
 	public function getBlockIdColumn(int $x, int $z) : string{
 		return "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00";
 	}
diff --git a/src/pocketmine/level/format/generic/GenericChunk.php b/src/pocketmine/level/format/generic/GenericChunk.php
index 5ad0583f7..8cb089603 100644
--- a/src/pocketmine/level/format/generic/GenericChunk.php
+++ b/src/pocketmine/level/format/generic/GenericChunk.php
@@ -281,7 +281,7 @@ class GenericChunk implements Chunk{
 			for($z = 0; $z < 16; ++$z){
 				$heightMap = $this->getHeightMap($x, $z);
 
-				$y = min($this->getHighestSubChunkIndex() << 4, $heightMap);
+				$y = min(($this->getHighestSubChunkIndex() + 1) << 4, $heightMap);
 
 				for(; $y > $heightMap; --$y){
 					$this->setBlockSkyLight($x, $y, $z, 15);
@@ -652,12 +652,7 @@ class GenericChunk implements Chunk{
 		$subChunks = [];
 		$count = $stream->getByte();
 		for($y = 0; $y < $count; ++$y){
-			$subChunks[$stream->getByte()] = new SubChunk(
-				$stream->get(4096), //blockIds
-				$stream->get(2048), //blockData
-				$stream->get(2048), //skyLight
-				$stream->get(2048)  //blockLight
-			);
+			$subChunks[$stream->getByte()] = SubChunk::fastDeserialize($stream->get(10240));
 		}
 		$heightMap = array_values(unpack("C*", $stream->get(256)));
 		$biomeIds = $stream->get(256);
diff --git a/src/pocketmine/level/format/generic/SubChunk.php b/src/pocketmine/level/format/generic/SubChunk.php
index 72e35c0cf..d19131d60 100644
--- a/src/pocketmine/level/format/generic/SubChunk.php
+++ b/src/pocketmine/level/format/generic/SubChunk.php
@@ -39,11 +39,11 @@ class SubChunk{
 		}
 	}
 
-	public function __construct(string $ids = "", string $data = "", string $blockLight = "", string $skyLight = ""){
+	public function __construct(string $ids = "", string $data = "", string $skyLight = "", string $blockLight = ""){
 		self::assignData($this->ids, $ids, 4096);
 		self::assignData($this->data, $data, 2048);
-		self::assignData($this->blockLight, $blockLight, 2048);
 		self::assignData($this->skyLight, $skyLight, 2048);
+		self::assignData($this->blockLight, $blockLight, 2048);
 	}
 
 	public function isEmpty() : bool{
@@ -115,26 +115,6 @@ class SubChunk{
 		return $changed;
 	}
 
-	public function getBlockSkyLight(int $x, int $y, int $z) : int{
-		$byte = ord($this->skyLight{($x << 7) + ($z << 3) + ($y >> 1)});
-		if(($y & 1) === 0){
-			return $byte & 0x0f;
-		}else{
-			return $byte >> 4;
-		}
-	}
-
-	public function setBlockSkyLight(int $x, int $y, int $z, int $level) : bool{
-		$i = ($x << 7) + ($z << 3) + ($y >> 1);
-		$byte = ord($this->skyLight{$i});
-		if(($y & 1) === 0){
-			$this->skyLight{$i} = chr(($byte & 0xf0) | ($level & 0x0f));
-		}else{
-			$this->skyLight{$i} = chr((($level & 0x0f) << 4) | ($byte & 0x0f));
-		}
-		return true;
-	}
-
 	public function getBlockLight(int $x, int $y, int $z) : int{
 		$byte = ord($this->blockLight{($x << 7) + ($z << 3) + ($y >> 1)});
 		if(($y & 1) === 0){
@@ -155,6 +135,26 @@ class SubChunk{
 		return true;
 	}
 
+	public function getBlockSkyLight(int $x, int $y, int $z) : int{
+		$byte = ord($this->skyLight{($x << 7) + ($z << 3) + ($y >> 1)});
+		if(($y & 1) === 0){
+			return $byte & 0x0f;
+		}else{
+			return $byte >> 4;
+		}
+	}
+
+	public function setBlockSkyLight(int $x, int $y, int $z, int $level) : bool{
+		$i = ($x << 7) + ($z << 3) + ($y >> 1);
+		$byte = ord($this->skyLight{$i});
+		if(($y & 1) === 0){
+			$this->skyLight{$i} = chr(($byte & 0xf0) | ($level & 0x0f));
+		}else{
+			$this->skyLight{$i} = chr((($level & 0x0f) << 4) | ($byte & 0x0f));
+		}
+		return true;
+	}
+
 	public function getHighestBlockAt(int $x, int $z) : int{
 		for($y = 15; $y >= 0; --$y){
 			if($this->ids{($x << 8) | ($z << 4) | $y} !== "\x00"){
@@ -191,23 +191,35 @@ class SubChunk{
 		return $this->data;
 	}
 
-	public function getBlockLightArray() : string{
-		assert(strlen($this->blockLight) === 2048, "Wrong length of light array, expecting 2048 bytes, got " . strlen($this->blockLight));
-		return $this->blockLight;
-	}
-
 	public function getSkyLightArray() : string{
 		assert(strlen($this->skyLight) === 2048, "Wrong length of skylight array, expecting 2048 bytes, got " . strlen($this->skyLight));
 		return $this->skyLight;
 	}
 
+	public function getBlockLightArray() : string{
+		assert(strlen($this->blockLight) === 2048, "Wrong length of light array, expecting 2048 bytes, got " . strlen($this->blockLight));
+		return $this->blockLight;
+	}
+
 	public function networkSerialize() : string{
 		// storage version, ids, data, skylight, blocklight
 		return "\x00" . $this->ids . $this->data . $this->skyLight . $this->blockLight;
 	}
 
 	public function fastSerialize() : string{
-		// ids, data, skylight, blocklight
-		return $this->ids . $this->data . $this->skyLight . $this->blockLight;
+		return
+			$this->ids .
+			$this->data .
+			$this->skyLight .
+			$this->blockLight;
+	}
+
+	public static function fastDeserialize(string $data) : SubChunk{
+		return new SubChunk(
+			substr($data,    0, 4096), //ids
+			substr($data, 4096, 2048), //data
+			substr($data, 6144, 2048), //sky light
+			substr($data, 8192, 2048)  //block light
+		);
 	}
 }
\ No newline at end of file
diff --git a/src/pocketmine/level/format/region/Anvil.php b/src/pocketmine/level/format/region/Anvil.php
index 250bb31d1..b385a8ddb 100644
--- a/src/pocketmine/level/format/region/Anvil.php
+++ b/src/pocketmine/level/format/region/Anvil.php
@@ -61,8 +61,8 @@ class Anvil extends McRegion{
 				"Y"          => new ByteTag("Y", $y),
 				"Blocks"     => new ByteArrayTag("Blocks",     GenericChunk::reorderByteArray($subChunk->getBlockIdArray())), //Generic in-memory chunks are currrently always XZY
 				"Data"       => new ByteArrayTag("Data",       GenericChunk::reorderNibbleArray($subChunk->getBlockDataArray())),
-				"BlockLight" => new ByteArrayTag("BlockLight", GenericChunk::reorderNibbleArray($subChunk->getBlockLightArray())),
-				"SkyLight"   => new ByteArrayTag("SkyLight",   GenericChunk::reorderNibbleArray($subChunk->getSkyLightArray()))
+				"SkyLight"   => new ByteArrayTag("SkyLight",   GenericChunk::reorderNibbleArray($subChunk->getSkyLightArray())),
+				"BlockLight" => new ByteArrayTag("BlockLight", GenericChunk::reorderNibbleArray($subChunk->getBlockLightArray()))
 			]);
 		}
 
@@ -119,8 +119,8 @@ class Anvil extends McRegion{
 						$subChunks[$subChunk->Y->getValue()] = new SubChunk(
 							GenericChunk::reorderByteArray($subChunk->Blocks->getValue()),
 							GenericChunk::reorderNibbleArray($subChunk->Data->getValue()),
-							GenericChunk::reorderNibbleArray($subChunk->BlockLight->getValue()),
-							GenericChunk::reorderNibbleArray($subChunk->SkyLight->getValue())
+							GenericChunk::reorderNibbleArray($subChunk->SkyLight->getValue()),
+							GenericChunk::reorderNibbleArray($subChunk->BlockLight->getValue())
 						);
 					}
 				}
diff --git a/src/pocketmine/level/format/region/McRegion.php b/src/pocketmine/level/format/region/McRegion.php
index 22d14b097..851582fb2 100644
--- a/src/pocketmine/level/format/region/McRegion.php
+++ b/src/pocketmine/level/format/region/McRegion.php
@@ -64,8 +64,8 @@ class McRegion extends BaseLevelProvider{
 
 		$ids = "";
 		$data = "";
-		$blockLight = "";
 		$skyLight = "";
+		$blockLight = "";
 		$subChunks = $chunk->getSubChunks();
 		for($x = 0; $x < 16; ++$x){
 			for($z = 0; $z < 16; ++$z){
@@ -73,8 +73,8 @@ class McRegion extends BaseLevelProvider{
 					$subChunk = $subChunks[$y];
 					$ids .= $subChunk->getBlockIdColumn($x, $z);
 					$data .= $subChunk->getBlockDataColumn($x, $z);
-					$blockLight .= $subChunk->getBlockLightColumn($x, $z);
 					$skyLight .= $subChunk->getSkyLightColumn($x, $z);
+					$blockLight .= $subChunk->getBlockLightColumn($x, $z);
 				}
 			}
 		}
@@ -138,8 +138,8 @@ class McRegion extends BaseLevelProvider{
 			$subChunks = [];
 			$fullIds = isset($chunk->Blocks) ? $chunk->Blocks->getValue() : str_repeat("\x00", 32768);
 			$fullData = isset($chunk->Data) ? $chunk->Data->getValue() : ($half = str_repeat("\x00", 16384));
-			$fullBlockLight = isset($chunk->BlockLight) ? $chunk->BlockLight->getValue() : $half;
 			$fullSkyLight = isset($chunk->SkyLight) ? $chunk->SkyLight->getValue() : str_repeat("\xff", 16384);
+			$fullBlockLight = isset($chunk->BlockLight) ? $chunk->BlockLight->getValue() : $half;
 
 			for($y = 0; $y < 8; ++$y){
 				$offset = ($y << 4);
@@ -154,19 +154,19 @@ class McRegion extends BaseLevelProvider{
 					$data .= substr($fullData, $offset, 8);
 					$offset += 64;
 				}
-				$blockLight = "";
-				$offset = ($y << 3);
-				for($i = 0; $i < 256; ++$i){
-					$blockLight .= substr($fullBlockLight, $offset, 8);
-					$offset += 64;
-				}
 				$skyLight = "";
 				$offset = ($y << 3);
 				for($i = 0; $i < 256; ++$i){
 					$skyLight .= substr($fullSkyLight, $offset, 8);
 					$offset += 64;
 				}
-				$subChunks[$y] = new SubChunk($ids, $data, $blockLight, $skyLight);
+				$blockLight = "";
+				$offset = ($y << 3);
+				for($i = 0; $i < 256; ++$i){
+					$blockLight .= substr($fullBlockLight, $offset, 8);
+					$offset += 64;
+				}
+				$subChunks[$y] = new SubChunk($ids, $data, $skyLight, $blockLight);
 			}
 
 			if(isset($chunk->BiomeColors)){
diff --git a/src/pocketmine/level/format/region/PMAnvil.php b/src/pocketmine/level/format/region/PMAnvil.php
index d1e9f0174..99ae99ff8 100644
--- a/src/pocketmine/level/format/region/PMAnvil.php
+++ b/src/pocketmine/level/format/region/PMAnvil.php
@@ -65,8 +65,8 @@ class PMAnvil extends Anvil{
 				"Y"          => new ByteTag("Y", $y),
 				"Blocks"     => new ByteArrayTag("Blocks",     $subChunk->getBlockIdArray()),
 				"Data"       => new ByteArrayTag("Data",       $subChunk->getBlockDataArray()),
-				"BlockLight" => new ByteArrayTag("BlockLight", $subChunk->getBlockLightArray()),
-				"SkyLight"   => new ByteArrayTag("SkyLight",   $subChunk->getSkyLightArray())
+				"SkyLight"   => new ByteArrayTag("SkyLight",   $subChunk->getSkyLightArray()),
+				"BlockLight" => new ByteArrayTag("BlockLight", $subChunk->getBlockLightArray())
 			]);
 		}
 
@@ -123,8 +123,8 @@ class PMAnvil extends Anvil{
 						$subChunks[$subChunk->Y->getValue()] = new SubChunk(
 							$subChunk->Blocks->getValue(),
 							$subChunk->Data->getValue(),
-							$subChunk->BlockLight->getValue(),
-							$subChunk->SkyLight->getValue()
+							$subChunk->SkyLight->getValue(),
+							$subChunk->BlockLight->getValue()
 						);
 					}
 				}