diff --git a/items.lua b/items.lua
index 63b40be..6effae4 100644
--- a/items.lua
+++ b/items.lua
@@ -19,7 +19,7 @@ local function show_map_id_formspec(id, player_x, player_z, player_name, height_
     local map = cartographer.get_map(id);
 
     player_x, player_z = cartographer.to_map_coordinates(map, player_x, player_z)
-    local formspec, formspec_width, formspec_height = cartographer.get_map_formspec_map(map, player_x, player_z, height_mode);
+    local formspec, formspec_width, _ = cartographer.get_map_formspec_map(map, player_x, player_z, height_mode);
     if #_cartographer.marker_lookup > 0 then
         formspec = formspec .. string.format("style_type[button,image_button,label;noclip=true] container[%f,1.0]", formspec_width - 0.01)
                             .. _cartographer.generate_marker_formspec(cartographer.get_marker(map, player_x, player_z), map.detail, marker_page or 1, cartographer.skin.marker_bg, cartographer.skin.marker_button)
@@ -92,7 +92,7 @@ minetest.register_on_player_receive_fields(function(player, name, fields)
             return;
         end
 
-        for k,v in pairs(fields) do
+        for k,_ in pairs(fields) do
             local marker = k:match("marker%-(.+)");
             local pos = player:get_pos();
             if marker or k == "clear_marker" then
@@ -141,10 +141,8 @@ minetest.register_node("cartographer:map", {
     -- Called when this node is placed in the world. Copies map data from the
     -- item to the node.
     -- pos: The position of the node
-    -- placer: The object that placed this node (can be nil)
     -- stack: The itemstack that was placed
-    -- pointed_thing: The current pointed thing
-    after_place_node = function(pos, placer, stack, pointed_thing)
+    after_place_node = function(pos, _, stack, _)
         local meta = stack:get_meta():to_table();
         local node_meta = minetest.get_meta(pos);
         node_meta:from_table(meta);
@@ -211,7 +209,7 @@ end
 
 -- Create a copy of the given map
 -- stack: An itemstack containing a map
--- 
+--
 -- Returns an itemstack with the copied map
 function cartographer.copy_map_item(stack)
     local meta = stack:get_meta();
@@ -224,11 +222,10 @@ function cartographer.copy_map_item(stack)
     local copy_meta = copy:get_meta();
 
     local id = meta:get_int("cartographer:map_id");
-    local new_id = 0;
     if id > 0 then
         local src = cartographer.get_map(id);
 
-        new_id = cartographer.create_map(src.x, src.z, src.w, src.h, false, src.detail, src.scale);
+        local new_id = cartographer.create_map(src.x, src.z, src.w, src.h, false, src.detail, src.scale);
         local dest = cartographer.get_map(new_id);
         for k,v in pairs(src.fill) do
             dest.fill[k] = v;