diff --git a/src/pocketmine/level/format/anvil/RegionLoader.php b/src/pocketmine/level/format/anvil/RegionLoader.php
index 5d102d470..b98b0ce14 100644
--- a/src/pocketmine/level/format/anvil/RegionLoader.php
+++ b/src/pocketmine/level/format/anvil/RegionLoader.php
@@ -88,6 +88,12 @@ class RegionLoader extends \pocketmine\level\format\mcregion\RegionLoader{
 			$compression = ord(fgetc($this->filePointer));
 		}
 
+		if($length >= self::MAX_SECTOR_LENGTH){
+			MainLogger::getLogger()->error("Corrupted chunk header detected");
+
+			return false;
+		}
+
 		if($length > ($this->locationTable[$index][1] << 12)){ //Invalid chunk, bigger than defined number of sectors
 			MainLogger::getLogger()->error("Corrupted chunk detected");
 			$this->locationTable[$index][1] = $length >> 12;
diff --git a/src/pocketmine/level/format/mcregion/RegionLoader.php b/src/pocketmine/level/format/mcregion/RegionLoader.php
index b5c9e33a7..8224e53d3 100644
--- a/src/pocketmine/level/format/mcregion/RegionLoader.php
+++ b/src/pocketmine/level/format/mcregion/RegionLoader.php
@@ -38,6 +38,7 @@ class RegionLoader{
 	const VERSION = 1;
 	const COMPRESSION_GZIP = 1;
 	const COMPRESSION_ZLIB = 2;
+	const MAX_SECTOR_LENGTH = 32 << 12; //32 sectors
 	public static $COMPRESSION_LEVEL = 7;
 
 	protected $x;
@@ -109,6 +110,12 @@ class RegionLoader{
 			$compression = ord(fgetc($this->filePointer));
 		}
 
+		if($length >= self::MAX_SECTOR_LENGTH){
+			MainLogger::getLogger()->error("Corrupted chunk header detected");
+
+			return false;
+		}
+
 		if($length > ($this->locationTable[$index][1] << 12)){ //Invalid chunk, bigger than defined number of sectors
 			MainLogger::getLogger()->error("Corrupted bigger chunk detected");
 			$this->locationTable[$index][1] = $length >> 12;