diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
new file mode 100644
index 0000000..37957f6
--- /dev/null
+++ b/.github/workflows/main.yml
@@ -0,0 +1,17 @@
+name: Lain
+
+on: [push]
+
+permissions:
+  contents: read
+
+jobs:
+  linting:
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Running tests triggered by a ${{ github.event_name }} event."
+      - run: echo "Testing ${{ github.ref }} from ${{ github.repository }} on ${{ runner.os }}"
+      - name: Check out code
+        uses: actions/checkout@v3
+      - name: Run tests
+        uses: lunarmodules/luacheck@v0
diff --git a/.luacheckrc b/.luacheckrc
new file mode 100644
index 0000000..9944223
--- /dev/null
+++ b/.luacheckrc
@@ -0,0 +1,27 @@
+-- Only allow symbols available in all Lua versions
+std = "min"
+
+allow_defined = true
+max_line_length = false
+cache = true
+
+-- Global objects defined by the C code
+read_globals = {
+    "awesome",
+    "mousegrabber",
+    "table.unpack",
+    "unpack",
+    "utf8"
+}
+
+globals = {
+    "client",
+    "mouse",
+    "root",
+    "screen"
+}
+
+-- https://luacheck.readthedocs.io/en/stable/warnings.html
+ignore = {
+    "131"
+}
diff --git a/README.rst b/README.rst
index 3d2f13f..616c7cd 100644
--- a/README.rst
+++ b/README.rst
@@ -1,6 +1,8 @@
 Lain
 ====
 
+.. image:: https://github.com/lcpz/lain/actions/workflows/main.yml/badge.svg
+
 -------------------------------------------------
 Layouts, widgets and utilities for Awesome WM 4.x
 -------------------------------------------------
diff --git a/helpers.lua b/helpers.lua
index 45f090f..ef9e08b 100644
--- a/helpers.lua
+++ b/helpers.lua
@@ -5,15 +5,15 @@
 
 --]]
 
-local spawn      = require("awful.spawn")
-local timer      = require("gears.timer")
-local debug      = require("debug")
-local io         = { lines = io.lines,
-                     open  = io.open }
-local pairs      = pairs
-local rawget     = rawget
-local table      = { sort  = table.sort, unpack = table.unpack }
-local unpack     = unpack or table.unpack -- lua 5.1 retro-compatibility
+local spawn  = require("awful.spawn")
+local timer  = require("gears.timer")
+local debug  = require("debug")
+local io     = { lines = io.lines,
+                 open  = io.open }
+local pairs  = pairs
+local rawget = rawget
+local tsort  = table.sort
+local unpack = unpack or table.unpack -- lua 5.1 retro-compatibility
 
 -- Lain helper functions for internal use
 -- lain.helpers
@@ -164,7 +164,7 @@ function helpers.spairs(t)
     local keys = {}
     for k in pairs(t) do keys[#keys+1] = k end
 
-    table.sort(keys)
+    tsort(keys)
 
     -- return the iterator function
     local i = 0
diff --git a/lain-scm-1.rockspec b/lain-scm-1.rockspec
index 6a76aba..70b0f43 100644
--- a/lain-scm-1.rockspec
+++ b/lain-scm-1.rockspec
@@ -6,16 +6,12 @@ source = {
 }
 description = {
    summary = "Layout, widgets and utilities for Awesome WM",
-   detailed = [[
-        Successor of awesome-vain, this module provides alternative layouts, asynchronous widgets and utility functions for Awesome WM.
-
-        Dependencies: curl (for IMAP, MPD and weather widgets); Glib >= 2.54 (for filesystems widget).
-    ]],
+   detailed = "Alternative layouts, asynchronous widgets and utility functions for Awesome WM. Non-Lua dependency: curl (for IMAP, MPD and weather widgets).",
    homepage = "https://github.com/lcpz/lain",
-   license = "GPL-2.0"
+   license = "GPL2"
 }
 dependencies = {
-   "lua >= 5.1",
+   "lua >= 5.3",
    "dkjson >= 2.6-1"
 }
 supported_platforms = { "linux" }
diff --git a/layout/centerwork.lua b/layout/centerwork.lua
index 142ccbe..c105676 100644
--- a/layout/centerwork.lua
+++ b/layout/centerwork.lua
@@ -10,7 +10,11 @@
 
 --]]
 
-local floor, max, mouse, mousegrabber, screen = math.floor, math.max, mouse, mousegrabber, screen
+local floor = math.floor
+local max = math.max
+local mouse = mouse
+local mousegrabber = mousegrabber
+local screen = screen
 
 local centerwork = {
     name       = "centerwork",
@@ -138,7 +142,7 @@ local function mouse_resize_handler(c, _, _, _, orientation)
         if g.height + 15 >= wa.height then
             offset = g.height * .5
             cursor = "sb_h_double_arrow"
-        elseif not (g.y + g.height + 15 > wa.y + wa.height) then
+        elseif g.y + g.height + 15 <= wa.y + wa.height then
             offset = g.height
         end
         corner_coords = { x = wa.x + wa.width * (1 - mwfact) / 2, y = g.y + offset }
@@ -146,7 +150,7 @@ local function mouse_resize_handler(c, _, _, _, orientation)
         if g.width + 15 >= wa.width then
             offset = g.width * .5
             cursor = "sb_v_double_arrow"
-        elseif not (g.x + g.width + 15 > wa.x + wa.width) then
+        elseif g.x + g.width + 15 <= wa.x + wa.width then
             offset = g.width
         end
         corner_coords = { y = wa.y + wa.height * (1 - mwfact) / 2, x = g.x + offset }
@@ -156,22 +160,22 @@ local function mouse_resize_handler(c, _, _, _, orientation)
 
     local prev_coords = {}
 
-    mousegrabber.run(function(_mouse)
+    mousegrabber.run(function(m)
         if not c.valid then return false end
-        for _, v in ipairs(_mouse.buttons) do
+        for _, v in ipairs(m.buttons) do
             if v then
-                prev_coords = { x = _mouse.x, y = _mouse.y }
+                prev_coords = { x = m.x, y = m.y }
                 local new_mwfact
                 if orientation == 'vertical' then
-                    new_mwfact = 1 - (_mouse.x - wa.x) / wa.width * 2
+                    new_mwfact = 1 - (m.x - wa.x) / wa.width * 2
                 else
-                    new_mwfact = 1 - (_mouse.y - wa.y) / wa.height * 2
+                    new_mwfact = 1 - (m.y - wa.y) / wa.height * 2
                 end
                 c.screen.selected_tag.master_width_factor = math.min(math.max(new_mwfact, 0.01), 0.99)
                 return true
             end
         end
-        return prev_coords.x == _mouse.x and prev_coords.y == _mouse.y
+        return prev_coords.x == m.x and prev_coords.y == m.y
     end, cursor)
 end
 
@@ -191,11 +195,14 @@ function centerwork.horizontal.mouse_resize_handler(c, corner, x, y)
     return mouse_resize_handler(c, corner, x, y, 'horizontal')
 end
 
--------------------------------------------------------------------------------
--- make focus.byidx and swap.byidx behave more consistently with other layouts
+
+--[[
+Make focus.byidx and swap.byidx behave more consistently with other layouts.
+--]]
 
 local awful = require("awful")
 local gears = require("gears")
+local client = client
 
 local function compare_position(a, b)
     if a.x == b.x then
@@ -208,7 +215,10 @@ end
 local function clients_by_position()
     local this = client.focus
     if this then
-        local sorted = client.focus.first_tag:clients()
+        local sorted = {}
+        for _, c in ipairs(client.focus.first_tag:clients()) do
+            if not c.minimized then sorted[#sorted+1] = c end
+        end
         table.sort(sorted, compare_position)
 
         local idx = 0
@@ -234,10 +244,9 @@ centerwork.focus = {}
 
 --[[
 Drop in replacements for awful.client.focus.byidx and awful.client.swap.byidx
-that behaves consistently with other layouts
+that behaves consistently with other layouts.
 --]]
 
-
 function centerwork.focus.byidx(i)
     if in_centerwork() then
         local cls = clients_by_position()
diff --git a/util/dkjson.lua b/util/dkjson.lua
index fadb5ef..61cccb9 100644
--- a/util/dkjson.lua
+++ b/util/dkjson.lua
@@ -42,8 +42,8 @@ SOFTWARE.
 --]==]
 
 -- global dependencies:
-local pairs, type, tostring, tonumber, getmetatable, setmetatable, rawset =
-      pairs, type, tostring, tonumber, getmetatable, setmetatable, rawset
+local pairs, type, tostring, tonumber, getmetatable, setmetatable =
+      pairs, type, tostring, tonumber, getmetatable, setmetatable
 local error, require, pcall, select = error, require, pcall, select
 local floor, huge = math.floor, math.huge
 local strrep, gsub, strsub, strbyte, strchar, strfind, strlen, strformat =
@@ -64,7 +64,7 @@ if register_global_module_table then
   end
 end
 
-local _ENV = nil -- blocking globals in Lua 5.2 and later
+_ENV = nil -- blocking globals in Lua 5.2 and later
 
 pcall (function()
   -- Enable access to blocked metatables.
@@ -252,7 +252,7 @@ local function exception(reason, value, state, buffer, buflen, defaultmessage)
   end
 end
 
-function json.encodeexception(reason, value, state, defaultmessage)
+function json.encodeexception(_reason, _value, _state, defaultmessage)
   return quotestring("<" .. defaultmessage .. ">")
 end
 
@@ -327,7 +327,7 @@ encode2 = function (value, indent, level, buffer, buflen, tables, globalorder, s
           local v = value[k]
           if v ~= nil then
             used[k] = true
-            buflen, msg = addpair (k, v, prev, indent, level, buffer, buflen, tables, globalorder, state)
+            buflen, _msg = addpair (k, v, prev, indent, level, buffer, buflen, tables, globalorder, state)
             prev = true -- add a seperator before the next element
           end
         end
@@ -510,7 +510,6 @@ end
 local scanvalue -- forward declaration
 
 local function scantable (what, closechar, str, startpos, nullval, objectmeta, arraymeta)
-  local len = strlen (str)
   local tbl, n = {}, 0
   local pos = startpos + 1
   if what == 'object' then
@@ -640,7 +639,7 @@ function json.use_lpeg ()
   local PlainChar = 1 - S"\"\\\n\r"
   local EscapeSequence = (P"\\" * g.C (S"\"\\/bfnrt" + Err "unsupported escape sequence")) / escapechars
   local HexDigit = R("09", "af", "AF")
-  local function UTF16Surrogate (match, pos, high, low)
+  local function UTF16Surrogate (_match, _pos, high, low)
     high, low = tonumber (high, 16), tonumber (low, 16)
     if 0xD800 <= high and high <= 0xDBff and 0xDC00 <= low and low <= 0xDFFF then
       return true, unichar ((high - 0xD800)  * 0x400 + (low - 0xDC00) + 0x10000)
diff --git a/util/separators.lua b/util/separators.lua
index ae384ec..04402bb 100644
--- a/util/separators.lua
+++ b/util/separators.lua
@@ -8,10 +8,11 @@
 
 local wibox = require("wibox")
 local gears = require("gears")
+local beautiful = require("beautiful")
 
 -- Lain Cairo separators util submodule
 -- lain.util.separators
-local separators = { height = 0, width = 9 }
+local separators = { height = beautiful.separators_height or 0, width = beautiful.separators_width or 9 }
 
 -- [[ Arrow
 
diff --git a/widget/temp.lua b/widget/temp.lua
index f636994..d478bd4 100644
--- a/widget/temp.lua
+++ b/widget/temp.lua
@@ -32,7 +32,11 @@ local function factory(args)
                     temp_now[t] = temp_value and temp_value/1e3 or temp_fl
                 end
             end
-            coretemp_now = string.format(format, temp_now[tempfile]) or "N/A"
+            if temp_now[tempfile] then
+                coretemp_now = string.format(format, temp_now[tempfile])
+            else
+                coretemp_now = "N/A"
+            end
             widget = temp.widget
             settings()
         end)
diff --git a/wiki b/wiki
index 74a423d..ad8081c 160000
--- a/wiki
+++ b/wiki
@@ -1 +1 @@
-Subproject commit 74a423dac2c8ea2f0f6827b209aa6de9b741a3a1
+Subproject commit ad8081cb3e3cb336323d1f72d34c7c8304490b14