diff --git a/mods/ITEMS/mcl_core/functions.lua b/mods/ITEMS/mcl_core/functions.lua
index 3d47336f..4b054cc2 100644
--- a/mods/ITEMS/mcl_core/functions.lua
+++ b/mods/ITEMS/mcl_core/functions.lua
@@ -48,6 +48,110 @@ minetest.register_abm({
 	end,
 })
 
+local function count_air_nodes_below(pos, limit)
+	local below_pos
+	local below_node
+	for i=1,limit do
+		below_pos = {x=pos.x, y=pos.y-i, z=pos.z}
+		below_node = minetest.get_node(below_pos)
+		if below_node.name ~= "air" then
+			return i - 1
+		end
+	end
+	return limit
+end
+
+local function flow_water_downwards(below_pos)
+	minetest.set_node(
+		below_pos,
+		{name="mcl_core:water_flowing", param2=15}
+	)
+	-- One could assume that the lava cooling ABM would now do its
+	-- job if water nodes end up next to lava nodes. This is never
+	-- entirely the case: The only way to get any reliable cooling
+	-- of lava nodes is to do it ourselves here … the lava is just
+	-- removed otherwise.
+	--
+	-- This might be due to an engine bug.
+	local beside_pos_list = {
+		{x=below_pos.x+1, y=below_pos.y, z=below_pos.z},
+		{x=below_pos.x-1, y=below_pos.y, z=below_pos.z},
+		{x=below_pos.x, y=below_pos.y, z=below_pos.z+1},
+		{x=below_pos.x, y=below_pos.y, z=below_pos.z-1},
+	}
+	local beside_node
+	local lavatype
+	for _, beside_pos in ipairs(beside_pos_list) do
+		beside_node = minetest.get_node(beside_pos)
+		if 0 ~= minetest.get_item_group(beside_node.name, "lava") then
+			lavatype = minetest.registered_nodes[beside_node.name].liquidtype
+			-- Lava flow → Cobblestone
+			if lavatype == "flowing" then
+				minetest.set_node(
+					beside_pos,
+					{name="mcl_core:cobble"}
+				)
+				-- Lava source → Obsidian
+			elseif lavatype == "source" then
+				minetest.set_node(
+					beside_pos,
+					{name="mcl_core:obsidian"}
+				)
+			end
+			-- Stone is generated if lava
+			-- ends up above water nodes,
+			-- this is handled elsewhere.
+			minetest.sound_play(
+				"fire_extinguish_flame",
+				{pos=beside_pos, gain=0.25, max_hear_distance=16},
+				true
+			)
+		end
+	end
+end
+
+minetest.register_abm({
+	label="Speed up downwards water flow and cool lava",
+	nodenames = {"mcl_core:water_flowing"},
+	neighbors = {"air"},
+	interval = 0.5,
+	chance = 1,
+	action = function(pos, node)
+		-- I want to start with an important message to every
+		-- future programmer who wants to rewrite the code in
+		-- a recursive fashion: STACK OVERFLOWS MEAN CRASHES!
+		--
+		-- Your recursive approach will most likely crash the
+		-- game – if not on your computer, then probably some
+		-- time later on some other computer. If you want the
+		-- questionable honor of being at fault when a bucket
+		-- of water can crash the server, go ahead: Refucktor
+		-- the code and be upset when it ruins someone's day.
+		--
+		-- After all, it really was not your fault, right? On
+		-- your computer everything worked and whoever has an
+		-- issue with your elegant solution just should buy a
+		-- new gaming rig or do something else beyond holding
+		-- you responsible for your utterly perfect solution.
+		--
+		-- In case this message offends you, I hereby ask you
+		-- to kindly fuck off, by which I mean: Stop reading.
+
+		-- We have to determine the depth of the air column
+		-- below the flowing water before changing anything
+		-- because otherwise we get artifacts in a lavacast
+		-- due to the lava escaping while we replace nodes.
+		local air_node_count = count_air_nodes_below(pos, 80)
+		if 0 == air_node_count then
+			return
+		end
+		for i=1,air_node_count do
+			local below_pos = {x=pos.x, y=pos.y-i, z=pos.z}
+			flow_water_downwards(below_pos)
+		end
+	end,
+})
+
 --
 -- Papyrus and cactus growing
 --