diff --git a/runtime/doc/filetype.txt b/runtime/doc/filetype.txt
index 466370aa0d..5010b2e4e0 100644
--- a/runtime/doc/filetype.txt
+++ b/runtime/doc/filetype.txt
@@ -136,6 +136,7 @@ what kind of file it is.  This doesn't always work.  A number of global
 variables can be used to overrule the filetype used for certain extensions:
 
 	file name	variable ~
+	`*.al`		g:filetype_al
 	`*.app`		g:filetype_app
 	`*.as`		g:filetype_as
 	`*.asa`		g:filetype_asa		|ft-aspperl-syntax|
diff --git a/runtime/lua/vim/filetype.lua b/runtime/lua/vim/filetype.lua
index 727c2b0601..7ed04bead6 100644
--- a/runtime/lua/vim/filetype.lua
+++ b/runtime/lua/vim/filetype.lua
@@ -245,6 +245,7 @@ local extension = {
   adb = 'ada',
   tdf = 'ahdl',
   aidl = 'aidl',
+  al = detect.al,
   a68 = 'algol68',
   aml = 'aml',
   run = 'ampl',
@@ -1006,7 +1007,6 @@ local extension = {
   plx = 'perl',
   prisma = 'prisma',
   psgi = 'perl',
-  al = 'perl',
   ctp = 'php',
   php = 'php',
   phpt = 'php',
diff --git a/runtime/lua/vim/filetype/detect.lua b/runtime/lua/vim/filetype/detect.lua
index 6bd14be841..e02db364a4 100644
--- a/runtime/lua/vim/filetype/detect.lua
+++ b/runtime/lua/vim/filetype/detect.lua
@@ -31,6 +31,37 @@ local matchregex = vim.filetype._matchregex
 -- luacheck: push no unused args
 -- luacheck: push ignore 122
 
+-- AL (Microsoft Dynamics 365 Business Central) or Perl AutoLoader
+--- @type vim.filetype.mapfn
+function M.al(_, bufnr)
+  if vim.g.filetype_al then
+    return vim.g.filetype_al
+  end
+  -- AL sources declare an object as "<kind> <id> <name>" at the start of a
+  -- line, optionally preceded by namespace and using declarations.  Perl
+  -- AutoLoader chunks match neither.  Matching a bare keyword anywhere would
+  -- be wrong: table, page and report are ordinary English words, so the object
+  -- name must follow.  The match is case sensitive because AL tooling emits
+  -- lowercase keywords, while prose in Perl comments is usually capitalised.
+  for _, line in ipairs(getlines(bufnr, 1, 200)) do
+    if
+      matchregex(
+        line,
+        [[^\s*\%(codeunit\|page\|pageextension\|pagecustomization\|table\|tableextension\|]]
+          .. [[report\|reportextension\|xmlport\|query\|enum\|enumextension\|profile\|profileextension\|]]
+          .. [[controladdin\|interface\|permissionset\|permissionsetextension\|entitlement\)\>\s\+\%(\d\|"\|\u\)]]
+      )
+      or findany(
+        line,
+        { '^%s*dotnet%s*$', '^%s*namespace%s+[%w._]+%s*;', '^%s*using%s+[%w._]+%s*;' }
+      )
+    then
+      return 'al'
+    end
+  end
+  return 'perl'
+end
+
 -- Erlang Application Resource Files (*.app.src is matched by extension)
 -- See: https://erlang.org/doc/system/applications
 --- @type vim.filetype.mapfn
diff --git a/test/old/testdir/test_filetype.vim b/test/old/testdir/test_filetype.vim
index ee52075079..c052cb214c 100644
--- a/test/old/testdir/test_filetype.vim
+++ b/test/old/testdir/test_filetype.vim
@@ -634,7 +634,7 @@ func s:GetFilenameChecks() abort
     \ 'pcmk': ['file.pcmk'],
     \ 'pdf': ['file.pdf'],
     \ 'pem': ['file.pem', 'file.cer', 'file.crt', 'file.csr'],
-    \ 'perl': ['file.plx', 'file.al', 'file.psgi', 'gitolite.rc', '.gitolite.rc', 'example.gitolite.rc', '.latexmkrc', 'latexmkrc'],
+    \ 'perl': ['file.plx', 'file.psgi', 'gitolite.rc', '.gitolite.rc', 'example.gitolite.rc', '.latexmkrc', 'latexmkrc'],
     \ 'pf': ['pf.conf'],
     \ 'pfmain': ['main.cf', 'main.cf.proto'],
     \ 'php': ['file.php', 'file.php9', 'file.phtml', 'file.ctp', 'file.phpt', 'file.theme'],
@@ -1264,6 +1264,57 @@ endfunc
 " Keep sorted.
 """""""""""""""""""""""""""""""""""""""""""""""""
 
+func Test_al_file()
+  filetype on
+
+  " AL object declaration
+  call writefile(['codeunit 50100 "My Codeunit"', '{', '}'], 'Xfile.al', 'D')
+  split Xfile.al
+  call assert_equal('al', &filetype)
+  bwipe!
+
+  " AL namespace and using declarations before the object
+  call writefile(['namespace Microsoft.Sales;', '', 'using Microsoft.Foundation;'], 'Xfile.al')
+  split Xfile.al
+  call assert_equal('al', &filetype)
+  bwipe!
+
+  " Perl AutoLoader chunk
+  call writefile(['# NOTE: Derived from blib/lib/Net/SSLeay.pm.', 'package Net::SSLeay;', 'sub do_https {'], 'Xfile.al')
+  split Xfile.al
+  call assert_equal('perl', &filetype)
+  bwipe!
+
+  " AL DotNet alias object, which is a bare keyword on its own line
+  call writefile(['dotnet', '{', '    assembly("mscorlib")', '}'], 'Xfile.al')
+  split Xfile.al
+  call assert_equal('al', &filetype)
+  bwipe!
+
+  " Perl code containing AL object kinds as ordinary words
+  call writefile(['sub value {', '  my $table = shift;', '  # report page interface', '}'], 'Xfile.al')
+  split Xfile.al
+  call assert_equal('perl', &filetype)
+  bwipe!
+
+  " Perl documentation containing AL object kinds at the start of a line
+  call writefile(['package Foo;', '=pod', 'Table of contents', 'using the -x option', 'table of contents follows'], 'Xfile.al')
+  split Xfile.al
+  call assert_equal('perl', &filetype)
+  bwipe!
+
+  " Test dist#ft#FTal()
+
+  let g:filetype_al = 'perl'
+  call writefile(['codeunit 50100 "My Codeunit"'], 'Xfile.al')
+  split Xfile.al
+  call assert_equal('perl', &filetype)
+  bwipe!
+  unlet g:filetype_al
+
+  filetype off
+endfunc
+
 " Since dist#ft#FTm4() looks around for configure.ac
 " the test needs to isolate itself in a fresh temporary project tree,
 " so that no configure.ac from another test (or from the repo root)