diff --git a/lisp/avoid.el b/lisp/avoid.el
index 167f97873ff..c9313563650 100644
--- a/lisp/avoid.el
+++ b/lisp/avoid.el
@@ -80,8 +80,8 @@
 (defcustom mouse-avoidance-mode nil
   "Activate mouse avoidance mode.  
 See function `mouse-avoidance-mode' for possible values.
-This variable should be set only with \\[customize], which is equivalent
-to using the function `mouse-avoidance-mode'."
+Setting this variable directly does not take effect;
+use either \\[customize] or the function `mouse-avoidance-mode'."
   :set (lambda (symbol value)
 	 ;; 'none below prevents toggling when value is nil.
 	 (mouse-avoidance-mode (or value 'none)))