diff --git a/runtime/ftplugin/m4.vim b/runtime/ftplugin/m4.vim
index 8702584..0ffe0ac 100644
--- a/runtime/ftplugin/m4.vim
+++ b/runtime/ftplugin/m4.vim
@@ -1,14 +1,20 @@
 " Vim filetype plugin file
 " Language:         m4
 " Maintainer:       Nikolai Weibull <now@bitwi.se>
-" Latest Revision:  2006-04-19
+" Latest Revision:  2008-07-09
 
 if exists("b:did_ftplugin")
   finish
 endif
 let b:did_ftplugin = 1
 
+let s:cpo_save = &cpo
+set cpo&vim
+
 let b:undo_ftplugin = "setl com< cms< fo<"
 
 setlocal comments=:#,:dnl commentstring=dnl\ %s
 setlocal formatoptions-=t formatoptions+=croql
+
+let &cpo = s:cpo_save
+unlet s:cpo_save