diff --git a/runtime/syntax/hgcommit.vim b/runtime/syntax/hgcommit.vim
index 37fe9db..e9f31be 100644
--- a/runtime/syntax/hgcommit.vim
+++ b/runtime/syntax/hgcommit.vim
@@ -1,8 +1,8 @@
 " Vim syntax file
-" Language:	hg (Mercurial) commit file
+" Language:	hg/sl (Mercurial / Sapling) commit file
 " Maintainer:	Ken Takata <kentkt at csc dot jp>
-" Last Change:	2012 Aug 23
-" Filenames:	hg-editor-*.txt
+"  		Max Coplan <mchcopl@gmail.com>
+" Last Change:	2022-12-08
 " License:	VIM License
 " URL:		https://github.com/k-takata/hg-vim
 
@@ -10,12 +10,15 @@
   finish
 endif
 
-syn match hgcommitComment "^HG:.*$"             contains=@NoSpell
-syn match hgcommitUser    "^HG: user: \zs.*$"   contains=@NoSpell contained containedin=hgcommitComment
-syn match hgcommitBranch  "^HG: branch \zs.*$"  contains=@NoSpell contained containedin=hgcommitComment
-syn match hgcommitAdded   "^HG: \zsadded .*$"   contains=@NoSpell contained containedin=hgcommitComment
-syn match hgcommitChanged "^HG: \zschanged .*$" contains=@NoSpell contained containedin=hgcommitComment
-syn match hgcommitRemoved "^HG: \zsremoved .*$" contains=@NoSpell contained containedin=hgcommitComment
+syn match hgcommitComment "^\%(SL\|HG\): .*$"            contains=@NoSpell
+syn match hgcommitUser    "^\%(SL\|HG\): user: \zs.*$"   contains=@NoSpell contained containedin=hgcommitComment
+syn match hgcommitBranch  "^\%(SL\|HG\): branch \zs.*$"  contains=@NoSpell contained containedin=hgcommitComment
+syn match hgcommitAdded   "^\%(SL\|HG\): \zsadded .*$"   contains=@NoSpell contained containedin=hgcommitComment
+syn match hgcommitChanged "^\%(SL\|HG\): \zschanged .*$" contains=@NoSpell contained containedin=hgcommitComment
+syn match hgcommitRemoved "^\%(SL\|HG\): \zsremoved .*$" contains=@NoSpell contained containedin=hgcommitComment
+
+syn region hgcommitDiff start=/\%(^\(SL\|HG\): diff --\%(git\|cc\|combined\) \)\@=/ end=/^\%(diff --\|$\|@@\@!\|[^[:alnum:]\ +-]\S\@!\)\@=/ fold contains=@hgcommitDiff
+syn include @hgcommitDiff syntax/shared/hgcommitDiff.vim
 
 hi def link hgcommitComment Comment
 hi def link hgcommitUser    String