As
Corion has already said, the use of
Exporter is frowned upon when writing classes, but if you really have to use it in such a way, then try rewriting
our @ISA = qw(Exporter); as
push @ISA, qw(Exporter); - in this way, rather than being overwritten,
@ISA is extended.
A user level that continues to overstate my experience :-))