confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"
if $args->{auto_deref}
- && $args->{isa} ne 'ArrayRef'
- && $args->{isa} ne 'HashRef';
+ && $args->{isa} !~ /^(?:ArrayRef|HashRef)(?:\[.*\])?$/;
if ($args->{trigger}) {
if (ref($args->{trigger}) eq 'HASH') {