diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1dcc2ffd5..d4aed0f8e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -53,7 +53,7 @@ jobs:
       - name: Run Test
         run: make test
 
-  lint:
+  stylua:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
@@ -65,6 +65,27 @@ jobs:
       - name: Lint
         run: make stylua-check
 
+  luals:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - uses: leafo/gh-actions-lua@v9
+        with:
+          luaVersion: "5.1.5"
+
+      - uses: leafo/gh-actions-luarocks@v4
+
+      - name: Download nvim-test
+        run: make nvim-test
+
+      - name: Download LuaLS
+        run: make luals
+
+      - name: Lint
+        run: make luals-check
+
   doc:
     runs-on: ubuntu-latest
     steps:
diff --git a/.gitignore b/.gitignore
index ce491757b..fbd0b84c0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,8 +2,7 @@ doc/tags
 
 scratch/dummy_ignored.txt
 
-luals
-
 nvim-test
-
 stylua
+luals
+luals_check
diff --git a/Makefile b/Makefile
index dd02ccc6e..ff623f6a5 100644
--- a/Makefile
+++ b/Makefile
@@ -83,8 +83,14 @@ build: gen_help stylua-run
 doc-check: gen_help
 	git diff --exit-code -- doc
 
-LUALS_VERSION := 3.7.4
-LUALS_TARBALL := lua-language-server-$(LUALS_VERSION)-$(shell uname -s)-$(shell uname -m).tar.gz
+ifeq ($(shell uname -m),arm64)
+    LUALS_ARCH ?= arm64
+else
+    LUALS_ARCH ?= x64
+endif
+
+LUALS_VERSION := 3.13.5
+LUALS_TARBALL := lua-language-server-$(LUALS_VERSION)-$(shell uname -s)-$(LUALS_ARCH).tar.gz
 LUALS_URL := https://github.com/LuaLS/lua-language-server/releases/download/$(LUALS_VERSION)/$(LUALS_TARBALL)
 
 luals:
@@ -97,6 +103,7 @@ luals:
 luals-check: luals nvim-test
 	VIMRUNTIME=$(XDG_DATA_HOME)/nvim-test/nvim-test-$(NVIM_TEST_VERSION)/share/nvim/runtime \
 		luals/bin/lua-language-server \
-			--logpath=. \
+			--logpath=luals_check \
 			--configpath=../.luarc.json \
 			--check=lua
+	@grep '^\[\]$$' luals_check/check.json
diff --git a/lua/gitsigns/diff_int.lua b/lua/gitsigns/diff_int.lua
index 001c369d1..341e28a88 100644
--- a/lua/gitsigns/diff_int.lua
+++ b/lua/gitsigns/diff_int.lua
@@ -3,7 +3,7 @@ local async = require('gitsigns.async')
 local create_hunk = require('gitsigns.hunks').create_hunk
 local config = require('gitsigns.config').config
 
-local decode
+local decode --- @type fun(data: string): any
 if jit and package.preload['string.buffer'] then
   decode = require('string.buffer').decode
 else
@@ -64,7 +64,7 @@ local run_diff_xdl_async = async.awrap(
             return bit.band(flags0, bit.lshift(1, pos)) ~= 0
           end
 
-          local encode
+          local encode --- @type fun(data: any): string
           if jit and package.preload['string.buffer'] then
             encode = require('string.buffer').encode
           else
diff --git a/lua/gitsigns/git.lua b/lua/gitsigns/git.lua
index e89fd7bf4..0a9b7cf1d 100644
--- a/lua/gitsigns/git.lua
+++ b/lua/gitsigns/git.lua
@@ -45,7 +45,9 @@ local git_command = require('gitsigns.git.cmd')
 --- @param file_buf string
 --- @param indent_heuristic? boolean
 --- @param diff_algo string
---- @return string[] stdout, string? stderr
+--- @return string[] stdout
+--- @return string? stderr
+--- @return integer code
 function M.diff(file_cmp, file_buf, indent_heuristic, diff_algo)
   return git_command({
     '-c',
diff --git a/lua/gitsigns/system/compat.lua b/lua/gitsigns/system/compat.lua
index 902447072..7e7c09560 100644
--- a/lua/gitsigns/system/compat.lua
+++ b/lua/gitsigns/system/compat.lua
@@ -333,6 +333,7 @@ local function system(cmd, opts, on_exit)
   if opts.timeout then
     state.timer = timer_oneshot(opts.timeout, function()
       if state.handle and state.handle:is_active() then
+        --- @diagnostic disable-next-line: invisible
         obj:_timeout()
       end
     end)