diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index 9ad3b5ec1dc1..9a54623e52d7 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -158,8 +158,8 @@ struct xen_vbd {
 	struct block_device	*bdev;
 	/* Cached size parameter. */
 	sector_t		size;
-	bool			flush_support;
-	bool			discard_secure;
+	unsigned int		flush_support:1;
+	unsigned int		discard_secure:1;
 };
 
 struct backend_info;