--- /dev/null
+use Modern::Perl;
+use Test::More tests => 1;
+use MARC::Record;
+
+use t::lib::Mocks;
+use C4::Biblio;
+
+t::lib::Mocks::mock_preference('marcflavour', 'MARC21');
+
+my $record = C4::Biblio::TransformKohaToMarc({
+ "biblioitems.illus" => "Other physical details", # 300$b
+ "biblioitems.pages" => "Extent", # 300$a
+ "biblioitems.size" => "Dimensions", # 300$c
+});
+
+my @subfields = $record->field('300')->subfields();
+is_deeply( \@subfields, [
+ [
+ 'a',
+ 'Extent'
+ ],
+ [
+ 'b',
+ 'Other physical details'
+ ],
+ [
+ 'c',
+ 'Dimensions'
+ ]
+ ],
+'TransformKohaToMarc should returns sorted subfields (regression test for bug 12343)' );