diff --git a/runtime/lua/vim/filetype/detect.lua b/runtime/lua/vim/filetype/detect.lua
index 1680c316bf..435303c829 100644
--- a/runtime/lua/vim/filetype/detect.lua
+++ b/runtime/lua/vim/filetype/detect.lua
@@ -936,7 +936,11 @@ function M.inc(path, bufnr)
     elseif findany(line, { '^%s{', '^%s%(%*' }) or matchregex(line, pascal_keywords) then
       return 'pascal'
     elseif
-      findany(line, { '^%s*inherit ', '^%s*require ', '^%s*%u[%w_:${}/]*%s+%??[?:+.]?=.? ' })
+      matchregex(line, [[\<\%(require\|inherit\)\>]])
+      or matchregex(
+        line,
+        [=[[A-Z][A-Za-z0-9_:${}/]*\(\[[A-Za-z0-9_:/]\+\]\)*\s\+\%(??\|[?:+.]\)\?=.\? ]=]
+      )
     then
       return 'bitbake'
     end
diff --git a/test/old/testdir/test_filetype.vim b/test/old/testdir/test_filetype.vim
index cbecf0f9ba..62b32b5e9e 100644
--- a/test/old/testdir/test_filetype.vim
+++ b/test/old/testdir/test_filetype.vim
@@ -2839,6 +2839,16 @@ func Test_inc_file()
   call assert_equal('bitbake', &filetype)
   bwipe!
 
+  call writefile(['FOO_BAR[baz] = "foobar"'], 'Xfile.inc')
+  split Xfile.inc
+  call assert_equal('bitbake', &filetype)
+  bwipe!
+
+  call writefile(['FOO_BAR_foo/bar[baz/bazzer] = "foobar"'], 'Xfile.inc')
+  split Xfile.inc
+  call assert_equal('bitbake', &filetype)
+  bwipe!
+
   call writefile(['MACHINEOVERRIDES =. "qemuall:"'], 'Xfile.inc')
   split Xfile.inc
   call assert_equal('bitbake', &filetype)