diff --git a/mods/CORE/mcl_init/init.lua b/mods/CORE/mcl_init/init.lua
index 54d4e5cd22..a410646a16 100644
--- a/mods/CORE/mcl_init/init.lua
+++ b/mods/CORE/mcl_init/init.lua
@@ -18,6 +18,8 @@ if mg_name ~= "flat" then
 	-- 1 flat bedrock layer with 4 rough layers above
 	mcl_vars.mg_bedrock_overworld_min = mcl_vars.mg_overworld_min
 	mcl_vars.mg_bedrock_overworld_max = mcl_vars.mg_bedrock_overworld_min + 4
+	mcl_vars.mg_lava_overworld_max = mcl_vars.mg_overworld_min + 10
+	mcl_vars.mg_lava = true
 	mcl_vars.mg_bedrock_is_rough = true
 else
 	local ground = minetest.get_mapgen_setting("mgflat_ground_level")
@@ -30,6 +32,7 @@ else
 	-- 1 perfectly flat bedrock layer
 	mcl_vars.mg_bedrock_overworld_min = mcl_vars.mg_overworld_min - 2
 	mcl_vars.mg_bedrock_overworld_max = mcl_vars.mg_bedrock_overworld_min
+	mcl_vars.mg_lava = false
 	mcl_vars.mg_bedrock_is_rough = false
 end
 
diff --git a/mods/MAPGEN/mcl_mapgen_core/init.lua b/mods/MAPGEN/mcl_mapgen_core/init.lua
index 4adabfa22d..b382193004 100644
--- a/mods/MAPGEN/mcl_mapgen_core/init.lua
+++ b/mods/MAPGEN/mcl_mapgen_core/init.lua
@@ -21,7 +21,7 @@ minetest.register_alias("mapgen_dirt_with_snow", "mcl_core:dirt_with_grass_snow"
 minetest.register_alias("mapgen_sand", "mcl_core:sand")
 minetest.register_alias("mapgen_gravel", "mcl_core:gravel")
 minetest.register_alias("mapgen_clay", "mcl_core:clay")
-minetest.register_alias("mapgen_lava_source", "mcl_core:lava_source")
+minetest.register_alias("mapgen_lava_source", "air") -- Built-in lava generator is too unpredictable, we generate lava on our own
 minetest.register_alias("mapgen_cobble", "mcl_core:cobble")
 minetest.register_alias("mapgen_mossycobble", "mcl_core:mossycobble")
 minetest.register_alias("mapgen_junglegrass", "mcl_flowers:fern")
@@ -521,7 +521,7 @@ minetest.register_ore({
 	ore_type       = "scatter",
 	ore            = "mcl_core:lava_source",
 	wherein         = stonelike,
-	clust_scarcity = 4000,
+	clust_scarcity = 2000,
 	clust_num_ores = 1,
 	clust_size     = 1,
 	y_min          = mcl_util.layer_to_y(1),
@@ -980,6 +980,7 @@ end)
 -- Generate bedrock layer or layers
 local BEDROCK_MIN = mcl_vars.mg_bedrock_overworld_min
 local BEDROCK_MAX = mcl_vars.mg_bedrock_overworld_max
+local GEN_MAX = mcl_vars.mg_lava_overworld_max or BEDROCK_MAX
 
 -- Buffer for LuaVoxelManip
 local lvm_buffer = {}
@@ -991,12 +992,14 @@ minetest.register_on_generated(function(minp, maxp)
 	local area = VoxelArea:new({MinEdge=emin, MaxEdge=emax})
 	local lvm_used = false
 
-	-- Generate bedrock layers
-	if minp.y <= BEDROCK_MAX then
+	-- Generate bedrock and lava layers
+	if minp.y <= GEN_MAX then
 		local c_bedrock = minetest.get_content_id("mcl_core:bedrock")
 		local c_void = minetest.get_content_id("mcl_core:void")
+		local c_lava = minetest.get_content_id("mcl_core:lava_source")
+		local c_air = minetest.get_content_id("air")
 
-		local max_y = math.min(maxp.y, BEDROCK_MAX)
+		local max_y = math.min(maxp.y, GEN_MAX)
 
 		for y = minp.y, max_y do
 			for x = minp.x, maxp.x do
@@ -1036,6 +1039,11 @@ minetest.register_on_generated(function(minp, maxp)
 					if setdata then
 						data[p_pos] = setdata
 						lvm_used = true
+					elseif mcl_vars.mg_lava and y <= mcl_vars.mg_lava_overworld_max then
+						if data[p_pos] == c_air then
+							data[p_pos] = c_lava
+						end
+						lvm_used = true
 					end
 				end
 			end
diff --git a/mods/MAPGEN/tsm_railcorridors/init.lua b/mods/MAPGEN/tsm_railcorridors/init.lua
index 959a752fff..a0ec0b78e5 100644
--- a/mods/MAPGEN/tsm_railcorridors/init.lua
+++ b/mods/MAPGEN/tsm_railcorridors/init.lua
@@ -73,7 +73,12 @@ if setting then
 end
 
 -- Max. and min. heights between rail corridors are generated
-local height_min = mcl_vars.mg_bedrock_overworld_max + 5 -- FIXME: Above lava layers
+local height_min
+if mcl_vars.mg_lava then
+	height_min = mcl_vars.mg_lava_overworld_max + 2
+else
+	height_min = mcl_vars.mg_bedrock_overworld_max + 2
+end
 local height_max = mcl_util.layer_to_y(60)
 
 -- Chaos Mode: If enabled, rail corridors don't stop generating when hitting obstacles
@@ -567,9 +572,9 @@ minetest.register_on_generated(function(minp, maxp, blockseed)
 	if minp.y < height_max and maxp.y > height_min and pr:next() < probability_railcaves_in_chunk then
 		-- Get semi-random height in chunk
 
-		local buffer = 5
-		local y = pr:next(minp.y + buffer, maxp.y - buffer)
-		y = math.floor(math.max(height_min, math.min(height_max, y)))
+		local buffer = 4
+		local y = pr:next(minp.y, maxp.y)
+		y = math.floor(math.max(height_min + buffer, math.min(height_max - buffer, y)))
 		local p = {x=minp.x+(maxp.x-minp.x)/2, y=y, z=minp.z+(maxp.z-minp.z)/2}
 		-- Haupthöhle und alle weiteren
 		-- Corridors; starting with main cave out of dirt