diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 63ba5ca..5f2a84a 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -67,6 +67,7 @@
 	atomic_t	openers;
 	sector_t	capacity;	/* size in 512-byte sectors */
 	u32		max_xfer_blocks;
+	u32		opt_xfer_blocks;
 	u32		max_ws_blocks;
 	u32		max_unmap_blocks;
 	u32		unmap_granularity;