diff --git a/settingtypes.txt b/settingtypes.txt
index d9204be..bd16a40 100644
--- a/settingtypes.txt
+++ b/settingtypes.txt
@@ -19,7 +19,7 @@ snow_debug (Debug Mode) bool false
 #Disable this to remove christmas saplings from being found.
 snow_christmas_content (Enable Christmas Content) bool true
 
-#Enables debug output. Currently it only prints mgv6 info.
+#Enables smooth biome transitions.
 snow_smooth_biomes (Smooth Biome Transitions) bool true
 
 #The minumum height a snow biome will generate (mgv7)
@@ -28,7 +28,8 @@ snow_min_height (Minumum Height for Snow Biomes) int 3
 #Disable this to stop snow from being smoothed.
 snow_smooth_snow (Multiple Snow Levels) bool true
 
-#mapgen rarity in %.
+#mapgen rarity in %. Note that this and mapgen_size do not work right because
+#sinus instead of Gauss curve is used as estimation.
 snow_mapgen_rarity (Snow Biome Rarity %) float 18
 
 #size of the generated… (has an effect to the rarity, too)
diff --git a/src/mapgen_v6.lua b/src/mapgen_v6.lua
index 5101d15..16fa1d4 100644
--- a/src/mapgen_v6.lua
+++ b/src/mapgen_v6.lua
@@ -255,7 +255,7 @@ minetest.register_on_generated(function(minp, maxp, seed)
 		if not in_biome then
 			if alpine
 			and test
-			and test >  smooth_rarity_min then
+			and test > (smooth and smooth_rarity_min or nosmooth_rarity) then
 				-- remove trees near alpine
 				local ground_y
 				if data[area:index(x, maxp.y, z)] == c.air then
@@ -345,7 +345,8 @@ minetest.register_on_generated(function(minp, maxp, seed)
 						data[area:index(x, ground_y+1, z)] = c.dry_shrub
 					else
 						if snowy
-						or test > smooth_rarity_max then
+						or test > (smooth and smooth_rarity_max or
+								nosmooth_rarity) then
 							-- more, deeper snow
 							data[node] = c.snow_block
 						else