diff --git a/runtime/ftplugin/m4.vim b/runtime/ftplugin/m4.vim
new file mode 100644
index 0000000..8f971e8
--- /dev/null
+++ b/runtime/ftplugin/m4.vim
@@ -0,0 +1,13 @@
+" Vim filetype plugin file
+" Language:         m4
+" Maintainer:       Nikolai Weibull <nikolai+work.vim@bitwi.se>
+" Latest Revision:  2005-06-29
+
+if exists("b:did_ftplugin")
+  finish
+endif
+let b:did_ftplugin = 1
+
+let b:undo_ftplugin = "setl com< cms<"
+
+setlocal comments=:#,:dnl commentstring=dnl\ %s