diff --git a/lisp/emacs-lisp/timer.el b/lisp/emacs-lisp/timer.el
index 54c5aff305a..0c66a207351 100644
--- a/lisp/emacs-lisp/timer.el
+++ b/lisp/emacs-lisp/timer.el
@@ -300,7 +300,11 @@ and idle timers such as are scheduled by `run-with-idle-timer'."
   "Third-to-last timer that was run.")
 
 (defvar timer-max-repeats 10
-  "*Maximum number of times to repeat a timer, if real time jumps.")
+  "*Maximum number of times to repeat a timer, if many repeats are delayed.
+Timer invocations can be delayed because Emacs is suspended or busy,
+or because the system's time changes.  If such an occurrence makes it
+appear that many invocations are overdue, this variable controls
+how many will really happen.")
 
 (defun timer-until (timer time)
   "Calculate number of seconds from when TIMER will run, until TIME.