diff --git a/src/pocketmine/level/format/Chunk.php b/src/pocketmine/level/format/Chunk.php
index 48716fd86..913eec200 100644
--- a/src/pocketmine/level/format/Chunk.php
+++ b/src/pocketmine/level/format/Chunk.php
@@ -79,8 +79,9 @@ interface Chunk{
 	 * @param int $blockId , if null, do not change
 	 * @param int $meta    0-15, if null, do not change
 	 *
+	 * @return bool
 	 */
-	public function setBlock(int $x, int $y, int $z, $blockId = null, $meta = null);
+	public function setBlock(int $x, int $y, int $z, $blockId = null, $meta = null) : bool;
 
 	/**
 	 * @param int $x 0-15
diff --git a/src/pocketmine/level/format/generic/GenericChunk.php b/src/pocketmine/level/format/generic/GenericChunk.php
index d5d4e0197..b180112ce 100644
--- a/src/pocketmine/level/format/generic/GenericChunk.php
+++ b/src/pocketmine/level/format/generic/GenericChunk.php
@@ -163,8 +163,8 @@ class GenericChunk implements Chunk{
 		return $this->getSubChunk($y >> 4)->getFullBlock($x, $y & 0x0f, $z);
 	}
 
-	public function setBlock(int $x, int $y, int $z, $blockId = null, $meta = null){
-		$this->getSubChunk($y >> 4, true)->setBlock($x, $y & 0x0f, $z, $blockId !== null ? ($blockId & 0xff) : null, $meta !== null ? ($meta & 0x0f) : null);
+	public function setBlock(int $x, int $y, int $z, $blockId = null, $meta = null) : bool{
+		return $this->getSubChunk($y >> 4, true)->setBlock($x, $y & 0x0f, $z, $blockId !== null ? ($blockId & 0xff) : null, $meta !== null ? ($meta & 0x0f) : null);
 	}
 
 	public function getBlockId(int $x, int $y, int $z) : int{