diff --git a/runtime/doc/os_unix.txt b/runtime/doc/os_unix.txt
index 6878842..fa49db8 100644
--- a/runtime/doc/os_unix.txt
+++ b/runtime/doc/os_unix.txt
@@ -30,8 +30,8 @@
 
 Because terminal updating under Unix is often slow (e.g. serial line
 terminal, shell window in suntools), the 'showcmd' and 'ruler' options
-are default off.  If you have a fast terminal, try setting them on.  You might
-also want to set 'ttyfast'.
+are off by default.  If you have a fast terminal, try setting them on.  You
+might also want to set 'ttyfast'.
 
 When using Vim in an xterm the mouse clicks can be used by Vim by setting
 'mouse' to "a".  If there is access to an X-server gui style copy/paste will