diff --git a/drivers/macintosh/rack-meter.c b/drivers/macintosh/rack-meter.c
index caaec654d7ea0..ba7e330640fba 100644
--- a/drivers/macintosh/rack-meter.c
+++ b/drivers/macintosh/rack-meter.c
@@ -227,6 +227,7 @@ static void rackmeter_do_timer(struct work_struct *work)
 
 	total_idle_ticks = get_cpu_idle_time(cpu);
 	idle_ticks = (unsigned int) (total_idle_ticks - rcpu->prev_idle);
+	idle_ticks = min(idle_ticks, total_ticks);
 	rcpu->prev_idle = total_idle_ticks;
 
 	/* We do a very dumb calculation to update the LEDs for now,