diff --git a/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c b/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c
index 3e81abe8e4..253c796c10 100644
--- a/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c
+++ b/linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c
@@ -551,7 +551,7 @@ static int blkif_queue_request(struct request *req)
 			lsect = fsect + (bvec->bv_len >> 9) - 1;
 			/* install a grant reference. */
 			ref = gnttab_claim_grant_reference(&gref_head);
-			ASSERT(ref != -ENOSPC);
+			BUG_ON(ref == -ENOSPC);
 
 			gnttab_grant_foreign_access_ref(
 				ref,
diff --git a/linux-2.6-xen-sparse/drivers/xen/netback/netback.c b/linux-2.6-xen-sparse/drivers/xen/netback/netback.c
index b8ed4fdfab..0124209b51 100644
--- a/linux-2.6-xen-sparse/drivers/xen/netback/netback.c
+++ b/linux-2.6-xen-sparse/drivers/xen/netback/netback.c
@@ -120,7 +120,7 @@ int netif_be_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	netif_t *netif = netdev_priv(dev);
 
-	ASSERT(skb->dev == dev);
+	BUG_ON(skb->dev != dev);
 
 	/* Drop the packet if the target domain has no receive buffers. */
 	if (!netif->active ||