diff --git a/.luacheckrc b/.luacheckrc
index 12cbefd..dd839e7 100644
--- a/.luacheckrc
+++ b/.luacheckrc
@@ -4,7 +4,7 @@ read_globals = {
 	"dump", "dump2",
 	"vector",
 	"VoxelManip", "VoxelArea",
-	"PseudoRandom", "PcgRandom",
+	"PseudoRandom", "PcgRandom", "PerlinNoiseMap",
 	"ItemStack",
 	"Settings",
 	"unpack",
diff --git a/map_formspec.lua b/map_formspec.lua
index 9fd7a40..4da62fe 100644
--- a/map_formspec.lua
+++ b/map_formspec.lua
@@ -36,7 +36,7 @@ local map_formspec_prefix = [[
 ]];
 
 local tile = "image[%f,%f;%f,%f;%s]";
-local marker = "animated_image[%f,%f;%f,%f;;%s;%d;%d]";
+local player_marker = "animated_image[%f,%f;%f,%f;;%s;%d;%d]";
 
 -- Generate formspec markup for an unknown biome tile
 -- x: The x position of the tile
@@ -113,11 +113,11 @@ local function generate_map(x, y, w, h, player_x, player_y, detail, map_scale, h
 
                     if i == player_x and j == player_y then
                         local player_icon = cartographer.detail_texture(cartographer.skin.player_icons, detail);
-                        str = str..marker:format(fx, fy - height,
-                                                 TILE_SIZE, TILE_SIZE,
-                                                 player_icon.texture .. ".png",
-                                                 player_icon.frame_count,
-                                                 player_icon.frame_duration);
+                        str = str .. player_marker:format(fx, fy - height,
+                                                          TILE_SIZE, TILE_SIZE,
+                                                          player_icon.texture .. ".png",
+                                                          player_icon.frame_count,
+                                                          player_icon.frame_duration);
                     end
                 else
                     str = str .. unknown_biome_tile(fx, fy, detail, get_variant(i - x, j - y, noise));
diff --git a/scanner.lua b/scanner.lua
index d9d3500..20ffad4 100644
--- a/scanner.lua
+++ b/scanner.lua
@@ -43,15 +43,11 @@ local function get_mapgen_biome(min, max, mmin, mmax)
     local heights = minetest.get_mapgen_object("heightmap");
 
     local xx = max.x - min.x;
-    local yy = max.y - min.y;
     local zz = max.z - min.z;
 
     local xxx = mmax.x - mmin.x;
-    local yyy = mmax.y - mmin.y;
-    local zzz = mmax.z - mmin.z;
 
     local startx = min.x - mmin.x;
-    local starty = min.y - mmin.y;
     local startz = min.z - mmin.z;
     
     local scan_biomes = {};
@@ -89,10 +85,6 @@ local function get_biome(min, max)
     local DEFAULT = minetest.get_biome_id("default");
     local WATER_SOURCE = minetest.registered_aliases["mapgen_water_source"];
 
-    local xx = max.x - min.x;
-    local yy = max.y - min.y;
-    local zz = max.z - min.z;
-
     local scan_biomes = {};
     local scan_heights = {};
 
@@ -131,12 +123,7 @@ local function get_biome(min, max)
     return biome, avg_height;
 end
 
-local function on_generated(min, max, blockseed)
-    local chunk = {
-        x = tochunk(min.x),
-        y = tochunk(min.z),
-    };
-
+local function on_generated(min, max, _)
     for i = tochunk(min.x),tochunk(max.x),1 do
         for j = tochunk(min.z),tochunk(max.z),1 do