diff --git a/src/pocketmine/block/CobblestoneWall.php b/src/pocketmine/block/CobblestoneWall.php
index 4e5b7ff3e..3d8c7bdc0 100644
--- a/src/pocketmine/block/CobblestoneWall.php
+++ b/src/pocketmine/block/CobblestoneWall.php
@@ -27,7 +27,7 @@ use pocketmine\item\Tool;
 use pocketmine\math\AxisAlignedBB;
 use pocketmine\math\Vector3;
 
-class CobblestoneWall extends Transparent{
+class CobblestoneWall extends Fence{
 	const NONE_MOSSY_WALL = 0;
 	const MOSSY_WALL = 1;
 
@@ -37,10 +37,6 @@ class CobblestoneWall extends Transparent{
 		$this->meta = $meta;
 	}
 
-	public function isSolid() : bool{
-		return false;
-	}
-
 	public function getToolType() : int{
 		return Tool::TYPE_PICKAXE;
 	}
@@ -57,38 +53,8 @@ class CobblestoneWall extends Transparent{
 		return "Cobblestone Wall";
 	}
 
-	protected function recalculateBoundingBox() : ?AxisAlignedBB{
-
-		$north = $this->canConnect($this->getSide(Vector3::SIDE_NORTH));
-		$south = $this->canConnect($this->getSide(Vector3::SIDE_SOUTH));
-		$west = $this->canConnect($this->getSide(Vector3::SIDE_WEST));
-		$east = $this->canConnect($this->getSide(Vector3::SIDE_EAST));
-
-		$n = $north ? 0 : 0.25;
-		$s = $south ? 1 : 0.75;
-		$w = $west ? 0 : 0.25;
-		$e = $east ? 1 : 0.75;
-
-		if($north and $south and !$west and !$east){
-			$w = 0.3125;
-			$e = 0.6875;
-		}elseif(!$north and !$south and $west and $east){
-			$n = 0.3125;
-			$s = 0.6875;
-		}
-
-		return new AxisAlignedBB(
-			$this->x + $w,
-			$this->y,
-			$this->z + $n,
-			$this->x + $e,
-			$this->y + 1.5,
-			$this->z + $s
-		);
-	}
-
-	public function canConnect(Block $block){
-		return ($block->getId() !== self::COBBLESTONE_WALL and $block->getId() !== self::FENCE_GATE) ? $block->isSolid() and !$block->isTransparent() : true;
+	public function getThickness() : float{
+		return 0.5;
 	}
 
 }
diff --git a/src/pocketmine/block/Fence.php b/src/pocketmine/block/Fence.php
index 2166854b7..6ee70e5d0 100644
--- a/src/pocketmine/block/Fence.php
+++ b/src/pocketmine/block/Fence.php
@@ -32,8 +32,12 @@ abstract class Fence extends Transparent{
 		$this->meta = $meta;
 	}
 
+	public function getThickness() : float{
+		return 0.25;
+	}
+
 	protected function recalculateBoundingBox() : ?AxisAlignedBB{
-		$width = 0.375;
+		$width = 0.5 - $this->getThickness() / 2;
 
 		return new AxisAlignedBB(
 			$this->x + ($this->canConnect($this->getSide(Vector3::SIDE_WEST)) ? 0 : $width),
@@ -45,6 +49,80 @@ abstract class Fence extends Transparent{
 		);
 	}
 
+	protected function recalculateCollisionBoxes() : array{
+		$inset = 0.5 - $this->getThickness() / 2;
+
+		$bbs = [
+			new AxisAlignedBB( //centre post AABB
+				$this->x + $inset,
+				$this->y,
+				$this->z + $inset,
+				$this->x + 1 - $inset,
+				$this->y + 1.5,
+				$this->z + 1 - $inset
+			)
+		];
+
+		if($this->canConnect($this->getSide(Vector3::SIDE_WEST))){
+			//western side connected part from start X to post (negative X)
+			//
+			// -#
+			//
+			$bbs[] = new AxisAlignedBB(
+				$this->x,
+				$this->y,
+				$this->z + $inset,
+				$this->x + $inset, //don't overlap with centre post
+				$this->y + 1.5,
+				$this->z + 1 - $inset
+			);
+		}
+		if($this->canConnect($this->getSide(Vector3::SIDE_EAST))){
+			//eastern side connected part from post to end X (positive X)
+			//
+			// #-
+			//
+			$bbs[] = new AxisAlignedBB(
+				$this->x + 1 - $inset,
+				$this->y,
+				$this->z + $inset,
+				$this->x + 1,
+				$this->y + 1.5,
+				$this->z + 1 - $inset
+			);
+		}
+		if($this->canConnect($this->getSide(Vector3::SIDE_NORTH))){
+			//northern side connected part from start Z to post (negative Z)
+			//  |
+			//  #
+			//
+			$bbs[] = new AxisAlignedBB(
+				$this->x + $inset,
+				$this->y,
+				$this->z,
+				$this->x + 1 - $inset,
+				$this->y + 1.5,
+				$this->z + $inset
+			);
+		}
+		if($this->canConnect($this->getSide(Vector3::SIDE_SOUTH))){
+			//southern side connected part from post to end Z (positive Z)
+			//
+			//  #
+			//  |
+			$bbs[] = new AxisAlignedBB(
+				$this->x + $inset,
+				$this->y,
+				$this->z + 1 - $inset,
+				$this->x + 1 - $inset,
+				$this->y + 1.5,
+				$this->z + 1
+			);
+		}
+
+		return $bbs;
+	}
+
 	public function canConnect(Block $block){
 		return $block instanceof static or $block instanceof FenceGate or ($block->isSolid() and !$block->isTransparent());
 	}