diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 82304b9..871a5bf 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -624,6 +624,7 @@
 extern xfs_agnumber_t	xfs_initialize_perag(struct bhv_vfs *, xfs_mount_t *,
 						xfs_agnumber_t);
 extern void	xfs_xlatesb(void *, struct xfs_sb *, int, __int64_t);
+extern int	xfs_sb_validate_fsb_count(struct xfs_sb *, __uint64_t);
 
 extern struct xfs_dmops xfs_dmcore_stub;
 extern struct xfs_qmops xfs_qmcore_stub;