diff --git a/src/pocketmine/math/Vector3.php b/src/pocketmine/math/Vector3.php
index 32a92ebda..36801282a 100644
--- a/src/pocketmine/math/Vector3.php
+++ b/src/pocketmine/math/Vector3.php
@@ -157,23 +157,20 @@ class Vector3{
 		}
 	}
 
-	public static function getOppositeSide($side){
-		switch((int) $side){
-			case Vector3::SIDE_DOWN:
-				return Vector3::SIDE_UP;
-			case Vector3::SIDE_UP:
-				return Vector3::SIDE_DOWN;
-			case Vector3::SIDE_NORTH:
-				return Vector3::SIDE_SOUTH;
-			case Vector3::SIDE_SOUTH:
-				return Vector3::SIDE_NORTH;
-			case Vector3::SIDE_WEST:
-				return Vector3::SIDE_EAST;
-			case Vector3::SIDE_EAST:
-				return Vector3::SIDE_WEST;
-			default:
-				return -1;
+	/**
+	 * Returns the Vector3 side number opposite the specified one
+	 *
+	 * @param int $side 0-5 one of the Vector3::SIDE_* constants
+	 * @return int
+	 *
+	 * @throws \InvalidArgumentException if an invalid side is supplied
+	 */
+	public static function getOppositeSide(int $side) : int{
+		if($side >= 0 and $side <= 5){
+			return $side ^ 0x01;
 		}
+
+		throw new \InvalidArgumentException("Invalid side $side given to getOppositeSide");
 	}
 
 	public function distance(Vector3 $pos){