--- a/lib/DNS/Vi.pm	Wed Jun 04 14:42:14 2014 +0200
+++ b/lib/DNS/Vi.pm	Wed Jun 04 14:47:45 2014 +0200
@@ -137,8 +137,8 @@
     my @out;
     my $origin = (grep { $_->{rrtype} eq 'SOA' } @zone)[0]->{label};
     my $ttl    = (grep { $_->{rrtype} eq 'SOA' } @zone)[0]->{ttl};
-    my $len1 = (sort map { index $_->{label}, '.' } @zone)[-1];
-    my $len2 = (sort map { length $_->{rrtype} } @zone)[-1];
+    my $len1 = (sort { $a <=> $b } map { index $_->{label}, '.' } @zone)[-1];
+    my $len2 = (sort { $a <=> $b } map { length $_->{rrtype} } @zone)[-1];
     push @out, "\$ORIGIN $origin", "\$TTL " . ttl2h($ttl);
 
     my $print = sub {