Update runtime files
diff --git a/runtime/indent/make.vim b/runtime/indent/make.vim
index 4483efd..76c8f83 100644
--- a/runtime/indent/make.vim
+++ b/runtime/indent/make.vim
@@ -1,7 +1,8 @@
 " Vim indent file
-" Language:             Makefile
-" Previous Maintainer:  Nikolai Weibull <now@bitwi.se>
-" Latest Revision:      2007-05-07
+" Language:		Makefile
+" Maintainer:		Doug Kearns <dougkearns@gmail.com>
+" Previous Maintainer:	Nikolai Weibull <now@bitwi.se>
+" Last Change:		24 Sep 2021
 
 if exists("b:did_indent")
   finish
@@ -12,6 +13,8 @@
 setlocal indentkeys=!^F,o,O,<:>,=else,=endif
 setlocal nosmartindent
 
+let b:undo_indent = "setl ai< inde< indk<"
+
 if exists("*GetMakeIndent")
   finish
 endif