diff --git a/fs/xfs/xfs_bmap_btree.c b/fs/xfs/xfs_bmap_btree.c
index 41092a2..32b49ec0 100644
--- a/fs/xfs/xfs_bmap_btree.c
+++ b/fs/xfs/xfs_bmap_btree.c
@@ -2309,7 +2309,7 @@
 		((xfs_bmbt_rec_base_t)blockcount &
 		(xfs_bmbt_rec_base_t)XFS_MASK64LO(21));
 #else	/* !XFS_BIG_BLKNOS */
-	if (ISNULLSTARTBLOCK(b)) {
+	if (ISNULLSTARTBLOCK(startblock)) {
 		r->l0 = ((xfs_bmbt_rec_base_t)extent_flag << 63) |
 			((xfs_bmbt_rec_base_t)startoff << 9) |
 			 (xfs_bmbt_rec_base_t)XFS_MASK64LO(9);
@@ -2369,7 +2369,7 @@
 		 ((xfs_bmbt_rec_base_t)blockcount &
 		  (xfs_bmbt_rec_base_t)XFS_MASK64LO(21)));
 #else	/* !XFS_BIG_BLKNOS */
-	if (ISNULLSTARTBLOCK(b)) {
+	if (ISNULLSTARTBLOCK(startblock)) {
 		r->l0 = cpu_to_be64(
 			((xfs_bmbt_rec_base_t)extent_flag << 63) |
 			 ((xfs_bmbt_rec_base_t)startoff << 9) |