diff --git a/libntfs/attrib.c b/libntfs/attrib.c
index f303d987..7951754b 100644
--- a/libntfs/attrib.c
+++ b/libntfs/attrib.c
@@ -3017,11 +3017,10 @@ static int ntfs_non_resident_attr_shrink(ntfs_attr *na, const s64 newsize)
 		/*
 		 * Reminder: It is ok for a->highest_vcn to be -1 for zero
 		 * length files.
-		 * FIXME: We may not update a->highest_vcn if it equal to 0.
-		 * But bug in runlist mapping code prevent us from doing so.
-		 * Find and remove this bug.
+		 * Reminder: We may not update a->highest_vcn if it equal to 0.
 		 */
-		a->highest_vcn = scpu_to_le64(first_free_vcn - 1);
+		if (a->highest_vcn)
+			a->highest_vcn = scpu_to_le64(first_free_vcn - 1);
 		/* Get the size for the new mapping pairs array. */
 		mp_size = ntfs_get_size_for_mapping_pairs(vol, na->rl);
 		if (mp_size <= 0) {
@@ -3365,11 +3364,10 @@ static int ntfs_non_resident_attr_expand(ntfs_attr *na, const s64 newsize)
 		na->allocated_size = first_free_vcn << vol->cluster_size_bits;
 		a->allocated_size = scpu_to_le64(na->allocated_size);
 		/*
-		 * FIXME: We may not update a->highest_vcn if it equal to 0.
-		 * But bug in runlist mapping code prevent us from doing so.
-		 * Find and remove this bug.
+		 * Reminder: We may not update a->highest_vcn if it equal to 0.
 		 */
-		a->highest_vcn = scpu_to_le64(first_free_vcn - 1);
+		if (a->highest_vcn)
+			a->highest_vcn = scpu_to_le64(first_free_vcn - 1);
 	}
 	/* Update the attribute record and the ntfs attribute structure. */
 	na->data_size = newsize;
@@ -3460,7 +3458,7 @@ int ntfs_attr_truncate(ntfs_attr *na, const s64 newsize)
 		return -1;
 	}
 	if (NAttrNonResident(na)) {
-		if (newsize > na->initialized_size)
+		if (newsize > na->data_size)
 			return ntfs_non_resident_attr_expand(na, newsize);
 		else
 			return ntfs_non_resident_attr_shrink(na, newsize);