diff --git a/ale_linters/dockerfile/hadolint.vim b/ale_linters/dockerfile/hadolint.vim
index 45b03aed..278e9466 100644
--- a/ale_linters/dockerfile/hadolint.vim
+++ b/ale_linters/dockerfile/hadolint.vim
@@ -55,13 +55,19 @@ function! ale_linters#dockerfile#hadolint#Handle(buffer, lines) abort
             let l:detail = 'hadolint could not parse the file because of a syntax error.'
         endif
 
-        call add(l:output, {
+        let l:line_output = {
         \   'lnum': l:lnum,
         \   'col': l:colnum,
         \   'type': l:type,
         \   'text': l:text,
         \   'detail': l:detail
-        \})
+        \}
+
+        if l:code isnot# ''
+            let l:line_output['code'] = l:code
+        endif
+
+        call add(l:output, l:line_output)
     endfor
 
     return l:output
diff --git a/test/handler/test_hadolint.vader b/test/handler/test_hadolint.vader
index a88454fa..f84c303d 100644
--- a/test/handler/test_hadolint.vader
+++ b/test/handler/test_hadolint.vader
@@ -16,6 +16,7 @@ Execute(The hadolint handler should handle a normal example):
   \     'lnum': 1,
   \     'col': 0,
   \     'type': 'W',
+  \     'code': 'DL3006',
   \     'text': "DL3006: Always tag the version of an image explicitly",
   \     'detail': "DL3006 ( https://github.com/hadolint/hadolint/wiki/DL3006 )\n\nAlways tag the version of an image explicitly",
   \   },
@@ -23,6 +24,7 @@ Execute(The hadolint handler should handle a normal example):
   \     'lnum': 4,
   \     'col': 0,
   \     'type': 'W',
+  \     'code': 'DL3033',
   \     'text': "DL3033: Specify version with `yum install -y <package>-<version>`.",
   \     'detail': "DL3033 ( https://github.com/hadolint/hadolint/wiki/DL3033 )\n\nSpecify version with `yum install -y <package>-<version>`.",
   \   },
@@ -30,6 +32,7 @@ Execute(The hadolint handler should handle a normal example):
   \     'lnum': 12,
   \     'col': 0,
   \     'type': 'W',
+  \     'code': 'SC2039',
   \     'text': "SC2039: In POSIX sh, brace expansion is undefined.",
   \     'detail': "SC2039 ( https://github.com/koalaman/shellcheck/wiki/SC2039 )\n\nIn POSIX sh, brace expansion is undefined.",
   \   },
diff --git a/test/test_dockerfile_hadolint_linter.vader b/test/test_dockerfile_hadolint_linter.vader
index 072cc524..6e02b212 100644
--- a/test/test_dockerfile_hadolint_linter.vader
+++ b/test/test_dockerfile_hadolint_linter.vader
@@ -68,14 +68,14 @@ Execute(command is correct when not docker):
 
 Execute(test warnings from hadolint):
   AssertEqual
-  \ [{'lnum': 10, 'col': 0, 'type': 'W', 'text': 'DL3007: Using latest is prone to errors', 'detail': "DL3007 ( https://github.com/hadolint/hadolint/wiki/DL3007 )\n\nUsing latest is prone to errors"}],
+  \ [{'lnum': 10, 'col': 0, 'type': 'W', 'code': 'DL3007', 'text': 'DL3007: Using latest is prone to errors', 'detail': "DL3007 ( https://github.com/hadolint/hadolint/wiki/DL3007 )\n\nUsing latest is prone to errors"}],
   \ ale_linters#dockerfile#hadolint#Handle(bufnr(''), [
   \ '-:10 DL3007 warning: Using latest is prone to errors',
   \ ])
 
 Execute(test warnings from shellcheck):
   AssertEqual
-  \ [{'lnum': 3, 'col': 0, 'type': 'W', 'text': 'SC2154: bar is referenced but not assigned.', 'detail': "SC2154 ( https://github.com/koalaman/shellcheck/wiki/SC2154 )\n\nbar is referenced but not assigned."}],
+  \ [{'lnum': 3, 'col': 0, 'type': 'W', 'code': 'SC2154', 'text': 'SC2154: bar is referenced but not assigned.', 'detail': "SC2154 ( https://github.com/koalaman/shellcheck/wiki/SC2154 )\n\nbar is referenced but not assigned."}],
   \ ale_linters#dockerfile#hadolint#Handle(bufnr(''), [
   \ '-:3 SC2154 warning: bar is referenced but not assigned.',
   \ ])