diff --git a/block/blk.h b/block/blk.h
index 95cab70..45385e9 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -188,6 +188,8 @@
 	return q->nr_congestion_off;
 }
 
+extern int blk_update_nr_requests(struct request_queue *, unsigned int);
+
 /*
  * Contribute to IO statistics IFF:
  *