diff --git a/mods/MAPGEN/mcl_dungeons/init.lua b/mods/MAPGEN/mcl_dungeons/init.lua
index d7e21fce6b..ca0d98f497 100644
--- a/mods/MAPGEN/mcl_dungeons/init.lua
+++ b/mods/MAPGEN/mcl_dungeons/init.lua
@@ -108,7 +108,7 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 	-- Check floor and ceiling: Must be *completely* solid
 	local y_floor = y
 	local y_ceiling = y + dim.y + 1
-	if check then for tx = x, x + dim.x do for tz = z, z + dim.z do
+	if check then for tx = x+1, x+dim.x do for tz = z+1, z+dim.z do
 		if not minetest.registered_nodes[mcl_mapgen_core.get_node({x = tx, y = y_floor  , z = tz}).name].walkable
 		or not minetest.registered_nodes[mcl_mapgen_core.get_node({x = tx, y = y_ceiling, z = tz}).name].walkable then return false end
 	end end end
@@ -121,36 +121,59 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 	-- so entities can get through.
 	local corners = {}
 
-	local walls = {
-		-- walls along x axis (contain corners)
-		{ x, x+dim.x+1, "x", "z", z },
-		{ x, x+dim.x+1, "x", "z", z+dim.z+1 },
-		-- walls along z axis (exclude corners)
-		{ z+1, z+dim.z, "z", "x", x },
-		{ z+1, z+dim.z, "z", "x", x+dim.x+1 },
-	}
+	local x2,z2 = x+dim.x+1, z+dim.z+1
 
-	for w=1, #walls do
-		local wall = walls[w]
-		for iter = wall[1], wall[2] do
-			local pos = {}
-			pos[wall[3]] = iter
-			pos[wall[4]] = wall[5]
-			pos.y = y+1
+	if mcl_mapgen_core.get_node({x=x, y=y+1, z=z}).name == "air" and mcl_mapgen_core.get_node({x=x, y=y+2, z=z}).name == "air" then
+		openings_counter = openings_counter + 1
+		if not openings[x] then openings[x]={} end
+		openings[x][z] = true
+		table.insert(corners, {x=x, z=z})
+	end
+	if mcl_mapgen_core.get_node({x=x2, y=y+1, z=z}).name == "air" and mcl_mapgen_core.get_node({x=x2, y=y+2, z=z}).name == "air" then
+		openings_counter = openings_counter + 1
+		if not openings[x2] then openings[x2]={} end
+		openings[x2][z] = true
+		table.insert(corners, {x=x2, z=z})
+	end
+	if mcl_mapgen_core.get_node({x=x, y=y+1, z=z2}).name == "air" and mcl_mapgen_core.get_node({x=x, y=y+2, z=z2}).name == "air" then
+		openings_counter = openings_counter + 1
+		if not openings[x] then openings[x]={} end
+		openings[x][z2] = true
+		table.insert(corners, {x=x, z=z2})
+	end
+	if mcl_mapgen_core.get_node({x=x2, y=y+1, z=z2}).name == "air" and mcl_mapgen_core.get_node({x=x2, y=y+2, z=z2}).name == "air" then
+		openings_counter = openings_counter + 1
+		if not openings[x2] then openings[x2]={} end
+		openings[x2][z2] = true
+		table.insert(corners, {x=x2, z=z2})
+	end
 
-			if openings[pos.x] == nil then openings[pos.x] = {} end
-			local doorname1 = mcl_mapgen_core.get_node(pos).name
-			pos.y = y+2
-			local doorname2 = mcl_mapgen_core.get_node(pos).name
-			if doorname1 == "air" and doorname2 == "air" then
-				openings_counter = openings_counter + 1
-				openings[pos.x][pos.z] = true
-
-				-- Record corners
-				if wall[3] == "x" and (iter == wall[1] or iter == wall[2]) then
-					table.insert(corners, {x=pos.x, z=pos.z})
-				end
-			end
+	for wx = x+1, x+dim.x do
+		if mcl_mapgen_core.get_node({x=wx, y=y+1, z=z}).name == "air" and mcl_mapgen_core.get_node({x=wx, y=y+2, z=z}).name == "air" then
+			openings_counter = openings_counter + 1
+			if check and openings_counter > 5 then return end
+			if not openings[wx] then openings[wx]={} end
+			openings[wx][z] = true
+		end
+		if mcl_mapgen_core.get_node({x=wx, y=y+1, z=z2}).name == "air" and mcl_mapgen_core.get_node({x=wx, y=y+2, z=z2}).name == "air" then
+			openings_counter = openings_counter + 1
+			if check and openings_counter > 5 then return end
+			if not openings[wx] then openings[wx]={} end
+			openings[wx][z2] = true
+		end
+	end
+	for wz = z+1, z+dim.z do
+		if mcl_mapgen_core.get_node({x=x, y=y+1, z=wz}).name == "air" and mcl_mapgen_core.get_node({x=x, y=y+2, z=wz}).name == "air" then
+			openings_counter = openings_counter + 1
+			if check and openings_counter > 5 then return end
+			if not openings[x] then openings[x]={} end
+			openings[x][wz] = true
+		end
+		if mcl_mapgen_core.get_node({x=x2, y=y+1, z=wz}).name == "air" and mcl_mapgen_core.get_node({x=x2, y=y+2, z=wz}).name == "air" then
+			openings_counter = openings_counter + 1
+			if check and openings_counter > 5 then return end
+			if not openings[x2] then openings[x2]={} end
+			openings[x2][wz] = true
 		end
 	end
 
@@ -178,6 +201,7 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 			openings[cx][czn] = true
 			openings_counter = openings_counter + 1
 			if openings_counter < 5 then
+				if not openings[cxn] then openings[cxn]={} end
 				openings[cxn][cz] = true
 				openings_counter = openings_counter + 1
 			end
@@ -199,7 +223,7 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 
 	-- We assign each position at the wall a number and each chest gets one of these numbers randomly
 	local totalChests = 2 -- this code strongly relies on this number being 2
-	local totalChestSlots = (dim.x-1) * (dim.z-1)
+	local totalChestSlots = (dim.x + dim.z - 2) * 2
 	local chestSlots = {}
 	-- There is a small chance that both chests have the same slot.
 	-- In that case, we give a 2nd chance for the 2nd chest to get spawned.
@@ -237,7 +261,7 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 		-- Do not overwrite nodes with is_ground_content == false (e.g. bedrock)
 		-- Exceptions: cobblestone and mossy cobblestone so neighborings dungeons nicely connect to each other
 		local name = mcl_mapgen_core.get_node(p).name
-		if name == "mcl_core:cobble" or name == "mcl_core:mossycobble" or minetest.registered_nodes[name].is_ground_content then
+		if minetest.registered_nodes[name].is_ground_content or name == "mcl_core:cobble" or name == "mcl_core:mossycobble" then
 			-- Floor
 			if ty == y then
 				if pr:next(1,4) == 1 then
@@ -251,16 +275,16 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 				The solid blocks above the dungeon are considered as the “ceiling”.
 				It is possible (but rare) for a dungeon to generate below sand or gravel. ]]
 
-			elseif ty > y and (tx == x or tx == maxx or (tz == z or tz == maxz)) then
+			elseif tx == x or tz == z or tx == maxx or tz == maxz then
 				-- Check if it's an opening first
-				if (not openings[tx][tz]) or ty == maxy then
+				if (ty == maxy) or (not (openings[tx] and openings[tx][tz]))  then
 					-- Place wall or ceiling
 					minetest.swap_node(p, {name = "mcl_core:cobble"})
 				elseif ty < maxy - 1 then
 					-- Normally the openings are already clear, but not if it is a corner
 					-- widening. Make sure to clear at least the bottom 2 nodes of an opening.
-					minetest.swap_node(p, {name = "air"})
-				elseif ty == maxy - 1 and mcl_mapgen_core.get_node(p).name ~= "air" then
+					if name ~= "air" then minetest.swap_node(p, {name = "air"}) end
+				elseif name ~= "air" then
 					-- This allows for variation between 2-node and 3-node high openings.
 					minetest.swap_node(p, {name = "mcl_core:cobble"})
 				end
@@ -268,6 +292,13 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 
 			-- Room interiour
 			else
+				if (ty==y+1) and (tx==x+1 or tx==maxx-1 or tz==z+1 or tz==maxz-1) and (currentChest < totalChests + 1) and (chestSlots[currentChest] == chestSlotCounter) then
+					currentChest = currentChest + 1
+					table.insert(chests, {x=tx, y=ty, z=tz})
+				else
+					minetest.swap_node(p, {name = "air"})
+				end
+
 				local forChest = ty==y+1 and (tx==x+1 or tx==maxx-1 or tz==z+1 or tz==maxz-1)
 
 				-- Place next chest at the wall (if it was its chosen wall slot)
@@ -275,7 +306,7 @@ local function ecb_spawn_dungeon(blockpos, action, calls_remaining, param)
 					currentChest = currentChest + 1
 					table.insert(chests, {x=tx, y=ty, z=tz})
 				else
-					minetest.swap_node(p, {name = "air"})
+					--minetest.swap_node(p, {name = "air"})
 				end
 				if forChest then
 					chestSlotCounter = chestSlotCounter + 1
@@ -341,9 +372,9 @@ local function dungeons_nodes(minp, maxp, blockseed)
 	local pr = PseudoRandom(blockseed)
 	for a=1, attempts do
 		local dim = dungeonsizes[pr:next(1, #dungeonsizes)]
-		local x = pr:next(minp.x, maxp.x-dim.x-2)
-		local y = pr:next(ymin  , ymax  -dim.y-2)
-		local z = pr:next(minp.z, maxp.z-dim.z-2)
+		local x = pr:next(minp.x, maxp.x-dim.x-1)
+		local y = pr:next(ymin  , ymax  -dim.y-1)
+		local z = pr:next(minp.z, maxp.z-dim.z-1)
 		local p1 = {x=x,y=y,z=z}
 		local p2 = {x = x+dim.x+1, y = y+dim.y+1, z = z+dim.z+1}
 		minetest.log("verbose","[mcl_dungeons] size=" ..minetest.pos_to_string(dim) .. ", emerge from "..minetest.pos_to_string(p1) .. " to " .. minetest.pos_to_string(p2))