diff --git a/runtime/doc/os_msdos.txt b/runtime/doc/os_msdos.txt
index 50fb4e8..d5be05f 100644
--- a/runtime/doc/os_msdos.txt
+++ b/runtime/doc/os_msdos.txt
@@ -12,4 +12,4 @@
 work on older systems.
 
 
- vim:tw=78:ts=8:ft=help:norl:
+ vim:tw=78:ts=8:noet:ft=help:norl: