diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 936dc7b..0ae2008e 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -822,6 +822,11 @@ static void bdi_update_dirty_ratelimit(struct backing_dev_info *bdi,
 	 */
 	balanced_dirty_ratelimit = div_u64((u64)task_ratelimit * write_bw,
 					   dirty_rate | 1);
+	/*
+	 * balanced_dirty_ratelimit ~= (write_bw / N) <= write_bw
+	 */
+	if (unlikely(balanced_dirty_ratelimit > write_bw))
+		balanced_dirty_ratelimit = write_bw;
 
 	/*
 	 * We could safely do this and return immediately: