diff --git a/src/pocketmine/level/Level.php b/src/pocketmine/level/Level.php
index 42443a28c..ccfdc8a09 100644
--- a/src/pocketmine/level/Level.php
+++ b/src/pocketmine/level/Level.php
@@ -1319,6 +1319,7 @@ class Level implements ChunkManager, Metadatable{
 	}
 
 	private function computeRemoveBlockLight(int $x, int $y, int $z, int $currentLight, \SplQueue $queue, \SplQueue $spreadQueue, array &$visited, array &$spreadVisited){
+		if($y < 0) return;
 		$current = $this->getBlockLightAt($x, $y, $z);
 
 		if($current !== 0 and $current < $currentLight){
@@ -1339,6 +1340,7 @@ class Level implements ChunkManager, Metadatable{
 	}
 
 	private function computeSpreadBlockLight(int $x, int $y, int $z, int $currentLight, \SplQueue $queue, array &$visited){
+		if($y < 0) return;
 		$current = $this->getBlockLightAt($x, $y, $z);
 
 		if($current < $currentLight){