diff --git a/sys/ufs/ffs/ffs_snapshot.c b/sys/ufs/ffs/ffs_snapshot.c
--- a/sys/ufs/ffs/ffs_snapshot.c
+++ b/sys/ufs/ffs/ffs_snapshot.c
@@ -1084,7 +1084,8 @@
 	dip->di_size = 0;
 	dip->di_blocks = 0;
 	dip->di_flags &= ~SF_SNAPSHOT;
-	bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs1_daddr_t));
+	bzero(dip->di_db, UFS_NDADDR * sizeof(ufs1_daddr_t));
+	bzero(dip->di_ib, UFS_NIADDR * sizeof(ufs1_daddr_t));
 	bdwrite(bp);
 	/*
 	 * Now go through and expunge all the blocks in the file
@@ -1366,7 +1367,8 @@
 	dip->di_size = 0;
 	dip->di_blocks = 0;
 	dip->di_flags &= ~SF_SNAPSHOT;
-	bzero(&dip->di_db[0], (UFS_NDADDR + UFS_NIADDR) * sizeof(ufs2_daddr_t));
+	bzero(dip->di_db, UFS_NDADDR * sizeof(ufs2_daddr_t));
+	bzero(dip->di_ib, UFS_NIADDR * sizeof(ufs2_daddr_t));
 	if (clearmode || cancelip->i_effnlink == 0)
 		dip->di_mode = 0;
 	else