How do you create a blessed reference to a constant hash?

I'm trying to create a proper blessed reference to a constant hash and the below code works but I'm not sure if its the proper 'Perl' way to do it.

package....

....
use Hash::Util qw<lock_hash>;

sub new {
    my ($self, $data, $left, $right) = @_;
    my %h = (DATA => $data, LEFT => $left, RIGHT => $right);
    my $r = bless \%h, $self;
    lock_hash($r->%*);
    $r;
}

1;

Any pointers or tips?

The Ullich update

package....

....
use Hash::Util qw<lock_hash>;

sub new {
    my ($self, $data, $left, $right) = @_;
    my %h = (DATA => $data, LEFT => $left, RIGHT => $right);
    lock_hashref(bless \%h, $self);#The Ullrich update
}

1;