diff --git a/kernel/time/timer.c b/kernel/time/timer.c
index d3f5e92f722a..74591ba9474f 100644
--- a/kernel/time/timer.c
+++ b/kernel/time/timer.c
@@ -874,7 +874,7 @@ unsigned long apply_slack(struct timer_list *timer, unsigned long expires)
 	if (mask == 0)
 		return expires;
 
-	bit = find_last_bit(&mask, BITS_PER_LONG);
+	bit = __fls(mask);
 
 	mask = (1UL << bit) - 1;