diff --git a/src/mapgen_v6.lua b/src/mapgen_v6.lua
index fc87111..9c7e95d 100644
--- a/src/mapgen_v6.lua
+++ b/src/mapgen_v6.lua
@@ -186,6 +186,7 @@ local function get_perlins(sidelen)
 	}
 end
 
+local nbuf_default, nbuf_cold, nbuf_ice
 minetest.register_on_generated(function(minp, maxp, seed)
 	local t1 = os.clock()
 
@@ -209,7 +210,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 	local pines_tab,pnum = {},1
 
 	get_perlins(x1 - x0 + 1)
-	local nvals_default = perlin_objs.default:get2dMap_flat{x=x0+150, y=z0+50}
+	local nvals_default = perlin_objs.default:get2dMap_flat({x=x0+150, y=z0+50}, nbuf_default)
 	local nvals_cold, nvals_ice, ndia
 
 	-- Choose biomes
@@ -236,9 +237,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 		local in_biome = false
 		local test
 		if nvals_default[ni] < 0.35 then
-			if not nvals_cold then
-				nvals_cold = perlin_objs.cold:get2dMap_flat{x=x0, y=z0}
-			end
+			nvals_cold = nvals_cold or perlin_objs.cold:get2dMap_flat({x=x0, y=z0}, nbuf_cold)
 			test = math.min(nvals_cold[ni], 1)
 			if smooth then
 				if test >= smooth_rarity_max
@@ -289,9 +288,12 @@ minetest.register_on_generated(function(minp, maxp, seed)
 				end
 			end
 		else
-			nodes_added = true
-			write_to_map = true
-			nvals_ice = nvals_ice or perlin_objs.ice:get2dMap_flat{x=x0, y=z0}
+			if not nvals_ice then
+				nvals_ice = perlin_objs.ice:get2dMap_flat({x=x0, y=z0}, nbuf_ice)
+
+				nodes_added = true
+				write_to_map = true
+			end
 			local icetype = nvals_ice[ni]
 			local cool = icetype > 0 -- only spawns ice on edge of water
 			local icebergs = icetype > -0.2 and icetype <= 0