diff --git a/block.h b/block.h
index e77988e..65c5166 100644
--- a/block.h
+++ b/block.h
@@ -191,6 +191,7 @@
 
 /* Ensure contents are flushed to disk.  */
 int bdrv_flush(BlockDriverState *bs);
+int coroutine_fn bdrv_co_flush(BlockDriverState *bs);
 void bdrv_flush_all(void);
 void bdrv_close_all(void);