diff --git a/src/API/BlockAPI.php b/src/API/BlockAPI.php
index 284538834..36f429793 100644
--- a/src/API/BlockAPI.php
+++ b/src/API/BlockAPI.php
@@ -397,9 +397,15 @@ class BlockAPI{
 		switch($data["block"]){
 			case 44: //Slabs
 				if($data["face"] === 0){
-					break;
+					if($target[0] === 44 and ($target[1] & 0x08) === 0x08 and ($target[1] & 0x07) === ($data["meta"] & 0x07)){
+						$replace = true;
+						$data["block"] = 43;
+						$data["meta"] = $data["meta"] & 0x07;
+					}else{
+						$data["meta"] |= 0x08;
+					}
 				}elseif($data["face"] === 1){
-					if(($target[1] & 0x07) === ($data["meta"] & 0x07) and $target[0] === 44){
+					if($target[0] === 44 and ($target[1] & 0x08) === 0 and ($target[1] & 0x07) === ($data["meta"] & 0x07)){
 						$replace = true;
 						$data["block"] = 43;
 						$data["meta"] = $data["meta"] & 0x07;
@@ -408,11 +414,16 @@ class BlockAPI{
 					$data2 = $data;
 					BlockFace::setPosition($data2, $data["face"]);
 					$b = $this->server->api->level->getBlock($data2["x"], $data2["y"], $data2["z"]);
-					if($b[0] === 44 and ($b[1] & 0x07) === ($data["meta"] & 0x07) and $b[0] === 44){
+					if($b[0] === 44 and ($b[1] & 0x07) === ($data["meta"] & 0x07)){
 						$data = $data2;
 						$replace = true;
 						$data["block"] = 43;
 						$data["meta"] = $data["meta"] & 0x07;
+					}else{
+						$data["meta"] = $data["meta"] & 0x07;
+						if($data["fy"] > 0.5){
+							$data["meta"] |= 0x08;
+						}
 					}
 				}
 				break;