diff --git a/airblock.lua b/airblock.lua
index 5a8109d..81a00a0 100644
--- a/airblock.lua
+++ b/airblock.lua
@@ -1,5 +1,12 @@
 local S = minetest.get_translator("tech_additions")
 
+local replace_allowed = {}
+replace_allowed["air"] = true
+replace_allowed["default:water_source"] = true
+replace_allowed["default:water_flowing"] = true
+replace_allowed["default:river_water_source"] = true
+replace_allowed["default:river_water_flowing"] = true
+
 local placeairblock = function ()
 	return function(itemstack, user, pointed_thing)
 		local name = user:get_player_name()
@@ -22,11 +29,7 @@ local placeairblock = function ()
 		end
 
 		local getPos = minetest.get_node(new_pos)
-		if getPos.name == "air" or
-				getPos.name == "default:water_source" or
-				getPos.name == "default:water_flowing" or
-				getPos.name == "default:river_water_source" or
-				getPos.name == "default:river_water_flowing" then
+		if replace_allowed[getPos.name] then
 			minetest.set_node(new_pos, {name="tech_additions:air_block"})
 		end
 	end