#!perl -w use strict; package MyClass; use Hash::FieldHash qw(:all); fieldhash my %foo => 'foo'; sub new{ my $class = shift; my $self = bless {}, $class; return from_hash($self, @_); } package MyDerivedClass; use parent -norequire => 'MyClass'; use Hash::FieldHash qw(:all); fieldhash my %bar => 'bar'; package main; my $o = MyDerivedClass->new(foo => 10, bar => 20); my $p = MyDerivedClass->new('MyClass::foo' => 10, 'MyDerivedClass::bar' => 20); use Data::Dumper; print Dumper($o->to_hash()); # $VAR1 = { foo => 10, bar => 20 } print Dumper($o->to_hash(-fully_qualify)); # $VAR1 = { 'MyClass::foo' => 10, 'MyDerived::bar' => 20 }