diff --git a/.github/workflows/luacheck.yml b/.github/workflows/luacheck.yml
new file mode 100644
index 0000000..5290e24
--- /dev/null
+++ b/.github/workflows/luacheck.yml
@@ -0,0 +1,11 @@
+on: [push, pull_request]
+name: luacheck
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+      - name: lint
+        uses: Roang-zero1/factorio-mod-luacheck@master
+        with:
+          luacheckrc_url: ""
diff --git a/.luacheckrc b/.luacheckrc
new file mode 100644
index 0000000..1d23b4a
--- /dev/null
+++ b/.luacheckrc
@@ -0,0 +1,21 @@
+unused = false
+
+globals = {
+	"currency", "barter",
+	"default"
+}
+
+read_globals = {
+	-- Lua
+	string = {fields = {"split", "trim"}},
+	table = {fields = {"copy", "getn"}},
+
+	-- Minetest
+	"minetest",
+	"PseudoRandom", "ItemStack",
+	"VoxelArea", "VoxelManip",
+	"Settings", "vector",
+
+	-- Mods
+	"loot", "pipeworks"
+}
diff --git a/barter.lua b/barter.lua
index 79b2124..86205b6 100644
--- a/barter.lua
+++ b/barter.lua
@@ -47,8 +47,8 @@ barter.chest.check_privilege = function(listname,playername,meta)
 end
 
 barter.chest.update_formspec = function(meta)
-	formspec = barter.chest.formspec.main
-	pl_formspec = function (n)
+	local formspec = barter.chest.formspec.main
+	local pl_formspec = function (n)
 		if meta:get_int(n.."step")==0 then
 			formspec = formspec .. barter.chest.formspec[n].start
 		else
@@ -65,9 +65,9 @@ barter.chest.update_formspec = function(meta)
 end
 
 barter.chest.give_inventory = function(inv,list,playername)
-	player = minetest.get_player_by_name(playername)
+	local player = minetest.get_player_by_name(playername)
 	if player then
-		for k,v in ipairs(inv:get_list(list)) do
+		for _,v in ipairs(inv:get_list(list)) do
 			if player:get_inventory():room_for_item("main",v) then
 				player:get_inventory():add_item("main",v)
 			else
@@ -144,7 +144,7 @@ minetest.register_node("currency:barter", {
 	on_receive_fields = function(pos, formname, fields, sender)
 		local meta = minetest.get_meta(pos)
 		barter.chest.start_timer(pos, meta)
-		pl_receive_fields = function(n)
+		local pl_receive_fields = function(n)
 			if fields[n.."_start"] and meta:get_string(n) == "" then
 				meta:set_string(n,sender:get_player_name())
 			end
diff --git a/income.lua b/income.lua
index 8f2354b..f701203 100644
--- a/income.lua
+++ b/income.lua
@@ -41,10 +41,10 @@ if income_enabled then
 		if not player or player.is_fake_player then return end
 		local name = player:get_player_name()
 
-		local income_count = players_income[name]
-		if income_count and income_count > 0 then
+		local ic = players_income[name]
+		if ic and ic > 0 then
 			local inv = player:get_inventory()
-			inv:add_item("main", {name=income_item, count=income_count})
+			inv:add_item("main", {name=income_item, count=ic})
 			players_income[name] = nil
 			minetest.log("info", "[Currency] added basic income for "..name.." to inventory")
 		end
diff --git a/shop.lua b/shop.lua
index 5af300e..627a906 100644
--- a/shop.lua
+++ b/shop.lua
@@ -61,7 +61,7 @@ end
 
 
 currency.shop.give_inventory = function(inv,list,playername)
-	player = minetest.get_player_by_name(playername)
+	local player = minetest.get_player_by_name(playername)
 	if player then
 		for k,v in ipairs(inv:get_list(list)) do
 			player:get_inventory():add_item("main",v)
@@ -238,7 +238,10 @@ minetest.register_node("currency:shop", {
 	can_dig = function(pos, player)
 		local meta = minetest.get_meta(pos)
 		local inv = meta:get_inventory()
-		return inv:is_empty("stock") and inv:is_empty("customers_gave") and inv:is_empty("owner_wants") and inv:is_empty("owner_gives")
+		return inv:is_empty("stock") and
+			inv:is_empty("customers_gave") and
+			inv:is_empty("owner_wants") and
+			inv:is_empty("owner_gives")
 	end
 })
 
@@ -305,7 +308,10 @@ minetest.register_node("currency:shop_empty", {
 	can_dig = function(pos, player)
 		local meta = minetest.get_meta(pos)
 		local inv = meta:get_inventory()
-		return inv:is_empty("stock") and inv:is_empty("customers_gave") and inv:is_empty("owner_wants") and inv:is_empty("owner_gives")
+		return inv:is_empty("stock") and
+			inv:is_empty("customers_gave") and
+			inv:is_empty("owner_wants") and
+			inv:is_empty("owner_gives")
 	end
 })