1 files changed, 8 insertions, 0 deletions

diff --git a/lisp/simple.el b/lisp/simple.el
index aeaebbffb34..b5723965665 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -4451,6 +4451,14 @@ See also `normal-erase-is-backspace'."
   (if (interactive-p)
       (message "Delete key deletes %s"
                (if normal-erase-is-backspace "forward" "backward"))))
+
+(defcustom idle-update-delay 0.5
+  "*Idle time delay before updating various things on the screen.
+Various Emacs features that update auxiliary information when point moves
+wait this many seconds after Emacs becomes idle before doing an update."
+  :type 'number
+  :group 'display
+  :version "21.4")
 
 
 ;; Minibuffer prompt stuff.