diff --git a/api.lua b/api.lua
index e1c49b3..e7fc566 100644
--- a/api.lua
+++ b/api.lua
@@ -3,7 +3,7 @@
 
 mobs = {}
 mobs.mod = "redo"
-mobs.version = "20180708"
+mobs.version = "20180710"
 
 
 -- Intllib
@@ -213,17 +213,17 @@ local get_distance = function(a, b)
 end
 
 
--- check line of sight (BrunoMine)
+-- check line of sight (by BrunoMine, tweaked by Astrobe)
 local line_of_sight = function(self, pos1, pos2, stepsize)
 
 	stepsize = stepsize or 1
 
+	local stepv = vector.multiply(vector.direction(pos1, pos2), stepsize)
+
 	local s, pos = minetest.line_of_sight(pos1, pos2, stepsize)
 
 	-- normal walking and flying mobs can see you through air
-	if s == true then
-		return true
-	end
+	if s == true then return true end
 
 	-- New pos1 to be analyzed
 	local npos1 = {x = pos1.x, y = pos1.y, z = pos1.z}
@@ -236,39 +236,15 @@ local line_of_sight = function(self, pos1, pos2, stepsize)
 	-- Nodename found
 	local nn = minetest.get_node(pos).name
 
-	-- Target Distance (td) to travel
-	local td = get_distance(pos1, pos2)
-
-	-- Actual Distance (ad) traveled
-	local ad = 0
-
 	-- It continues to advance in the line of sight in search of a real
 	-- obstruction which counts as 'normal' nodebox.
 	while minetest.registered_nodes[nn]
 	and (minetest.registered_nodes[nn].walkable == false
 	or minetest.registered_nodes[nn].drawtype == "nodebox") do
 
-		-- Check if you can still move forward
-		if td < ad + stepsize then
-			return true -- Reached the target
-		end
+		npos1 = vector.add(npos1, stepv)
 
-		-- Moves the analyzed pos
-		local d = get_distance(pos1, pos2)
-
-		npos1.x = ((pos2.x - pos1.x) / d * stepsize) + pos1.x
-		npos1.y = ((pos2.y - pos1.y) / d * stepsize) + pos1.y
-		npos1.z = ((pos2.z - pos1.z) / d * stepsize) + pos1.z
-
-		-- NaN checks
-		if d == 0
-		or npos1.x ~= npos1.x
-		or npos1.y ~= npos1.y
-		or npos1.z ~= npos1.z then
-			return false
-		end
-
-		ad = ad + stepsize
+		if get_distance(npos1, pos2) < stepsize then return true end
 
 		-- scan again
 		r, pos = minetest.line_of_sight(npos1, pos2, stepsize)
@@ -277,7 +253,6 @@ local line_of_sight = function(self, pos1, pos2, stepsize)
 
 		-- New Nodename found
 		nn = minetest.get_node(pos).name
-
 	end
 
 	return false
diff --git a/crafts.lua b/crafts.lua
index 0bf42ad..0460f89 100644
--- a/crafts.lua
+++ b/crafts.lua
@@ -146,6 +146,37 @@ default.register_fence("mobs:fence_wood", {
 	},
 })
 
+-- mob fence top (has enlarged collisionbox to stop mobs getting over)
+	minetest.register_node("mobs:fence_top", {
+		description = S("Mob Fence Top"),
+		drawtype = "nodebox",
+		tiles = {"default_wood.png"},
+		paramtype = "light",
+		is_ground_content = false,
+		groups = {choppy = 2, oddly_breakable_by_hand = 2, flammable = 2},
+		sounds = default.node_sound_wood_defaults(),
+		node_box = {
+			type = "fixed",
+			fixed = {-0.2, -0.5, -0.2, 0.2, 0, 0.2},
+		},
+		collision_box = {
+			type = "fixed",
+			fixed = {-0.4, -1.5, -0.4, 0.4, 0, 0.4},
+		},
+		selection_box = {
+			type = "fixed",
+			fixed = {-0.4, -1.5, -0.4, 0.4, 0, 0.4},
+		},
+})
+
+minetest.register_craft({
+	output = "mobs:fence_top 12",
+	recipe = {
+		{"group:wood", "group:wood", "group:wood"},
+		{"", "default:fence_wood", ""},
+	}
+})
+
 -- items that can be used as fuel
 minetest.register_craft({
 	type = "fuel",
@@ -182,3 +213,9 @@ minetest.register_craft({
 	recipe = "mobs:fence_wood",
 	burntime = 7,
 })
+
+minetest.register_craft({
+	type = "fuel",
+	recipe = "mobs:fence_top",
+	burntime = 2,
+})
diff --git a/lucky_block.lua b/lucky_block.lua
index 8cf20ed..ef7d59c 100644
--- a/lucky_block.lua
+++ b/lucky_block.lua
@@ -12,6 +12,7 @@ if minetest.get_modpath("lucky_block") then
 		{"dro", {"mobs:shears"}, 1},
 		{"dro", {"mobs:protector"}, 1},
 		{"dro", {"mobs:fence_wood"}, 10},
+		{"dro", {"mobs:fence_top"}, 12},
 		{"lig"},
 	})
 end
diff --git a/readme.MD b/readme.MD
index 714945d..af984e9 100644
--- a/readme.MD
+++ b/readme.MD
@@ -17,11 +17,13 @@ Crafts:
  - Magic Lasso is similar to nets but with a better chance of picking up larger mobs.
  - Shears are used to right-click sheep and return 1-3 wool.
  - Protection Rune lets you protect tamed mobs from harm by other players
+ - Mob Fence and Fence Top (to stop mobs escaping/glitching through fences)
 
 Lucky Blocks: 9
 
 
 Changelog:
+- 1.45- Added Fence Top to add on top of any fence to stop mobs escaping, new line_of_sight tweaked by Astrobe
 - 1.44- Added ToolRanks support for swords when attacking mobs
 - 1.43- Better 0.4.16 compatibility, added general attack function and settings
 - 1.42- Added "all" option to immune_to table, tidied floating mobs to be less intensive