sub initialize_slot {
my ($self, $instance, $slot_name) = @_;
- $self->{meta}->add_package_variable('%' . $slot_name);
+ $self->{meta}->add_package_variable(('%' . $slot_name) => {});
$self->{meta}->get_package_variable('%' . $slot_name)->{refaddr $instance} = undef;
}