diff --git a/nbd.h b/nbd.h
index 4bb185b..01e4a6a 100644
--- a/nbd.h
+++ b/nbd.h
@@ -33,7 +33,8 @@
 int nbd_negotiate(BlockDriverState *bs, int csock, off_t size);
 int nbd_receive_negotiate(int csock, off_t *size, size_t *blocksize);
 int nbd_init(int fd, int csock, off_t size, size_t blocksize);
-int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset, off_t *offset, bool readonly);
+int nbd_trip(BlockDriverState *bs, int csock, off_t size, uint64_t dev_offset,
+             off_t *offset, bool readonly, uint8_t *data, int data_size);
 int nbd_client(int fd, int csock);
 int nbd_disconnect(int fd);