diff --git a/contrib/hg-test-mode.el b/contrib/hg-test-mode.el
new file mode 100644
--- /dev/null
+++ b/contrib/hg-test-mode.el
@@ -0,0 +1,55 @@
+;; hg-test-mode.el - Major mode for editing Mercurial tests
+;;
+;; Copyright 2014 Matt Mackall <mpm@selenic.com>
+;; "I have no idea what I'm doing"
+;;
+;; This software may be used and distributed according to the terms of the
+;; GNU General Public License version 2 or any later version.
+;;
+;; To enable, add something like the following to your .emacs:
+;;
+;; (if (file-exists-p "~/hg/contrib/hg-test-mode.el")
+;;    (load "~/hg/contrib/hg-test-mode.el"))
+
+(defvar hg-test-mode-hook nil)
+
+(defvar hg-test-mode-map
+  (let ((map (make-keymap)))
+    (define-key map "\C-j" 'newline-and-indent)
+    map)
+  "Keymap for hg test major mode")
+
+(add-to-list 'auto-mode-alist '("\\.t\\'" . hg-test-mode))
+
+(defconst hg-test-font-lock-keywords-1
+  (list
+   '("^  \\(\\$\\|>>>\\) " 1 font-lock-builtin-face)
+   '("^  \\(>\\|\\.\\.\\.\\) " 1 font-lock-constant-face)
+   '("^  \\([[][0-9]+[]]\\)$" 1 font-lock-warning-face)
+   '("^  \\(.*?\\)\\(\\( [(][-a-z]+[)]\\)+\\)$" 2 font-lock-type-face)
+   '("^  \\(.*?\\)\\(\\( [(][-a-z]+[)]\\)*\\)$" 1 font-lock-string-face)
+   '("^#.*" . font-lock-preprocessor-face)
+   '("^\\([^ ].*\\)$" 1 font-lock-comment-face)
+   )
+  "Minimal highlighting expressions for hg-test mode")
+
+(defvar hg-test-font-lock-keywords hg-test-font-lock-keywords-1
+  "Default highlighting expressions for hg-test mode")
+
+(defvar hg-test-mode-syntax-table
+  (let ((st (make-syntax-table)))
+    (modify-syntax-entry ?\" "w" st) ;; disable standard quoting
+    st)
+"Syntax table for hg-test mode")
+
+(defun hg-test-mode ()
+  (interactive)
+  (kill-all-local-variables)
+  (use-local-map hg-test-mode-map)
+  (set-syntax-table hg-test-mode-syntax-table)
+  (set (make-local-variable 'font-lock-defaults) '(hg-test-font-lock-keywords))
+  (setq major-mode 'hg-test-mode)
+  (setq mode-name "hg-test")
+  (run-hooks 'hg-test-mode-hook))
+
+(provide 'hg-test-mode)