diff --git a/objects/enemy/spider.gd b/objects/enemy/spider.gd
index 048b16d..4550a79 100644
--- a/objects/enemy/spider.gd
+++ b/objects/enemy/spider.gd
@@ -12,6 +12,9 @@ export var down_boundary = 0
 #var floor_y = 0.0
 
 func _ready():
+	down_boundary = max(5.0, hitbox.position.y + down_boundary * 8.0)
+	up_boundary = max(5.0, hitbox.position.y - up_boundary * 8.0)
+	
 	var raycast = $RayCast2D
 	# detect ceiling
 	raycast.force_raycast_update()
@@ -19,17 +22,12 @@ func _ready():
 	global_position.y = raycast.get_collision_point().y
 	hitbox.global_position.y = old_y
 	line.points[1].y = hitbox.position.y
-	# detect floor
-	raycast.cast_to = Vector2(0.0, 192.0)
-	raycast.force_raycast_update()
-	#floor_y = to_local(raycast.get_collision_point()).y - 3
-	down_boundary *= 8
 	raycast.queue_free()
 
 func _physics_process(delta):
 	hitbox.position.y += direction * speed * delta
-	if hitbox.position.y < 5.0:
-		hitbox.position.y = 5.0
+	if hitbox.position.y < up_boundary:
+		hitbox.position.y = up_boundary
 		direction = 1.0
 	if hitbox.position.y > down_boundary:
 		hitbox.position.y = down_boundary