Unexpected behaviour when reregistering plugins

mojo-test.pl

#!/usr/bin/perl

use Mojolicious::Lite;

plugin 'wordlist';

app->words('banana');

plugin 'wordlist';

app->words('apple');
app->words('cherry');

app->start;

Mojolicious::Plugin::Wordlist.pm

package Mojolicious::Plugin::Wordlist;
use Mojo::Base 'Mojolicious::Plugin';

sub register {
    my ($plugin, $mojo) = @_;

    $plugin->{text} = "Wordlist:\n";

    $mojo->helper(
	'words' => sub {
	    return $plugin->add(@_);
	}
	);

    $mojo->routes->route('/')->to(
	cb => sub {
	    shift->render_text($plugin->{text});
	}
	);

};

sub add {
    my ($plugin, $c, $word) = @_;
    $plugin->{text} .= $word."\n";
};

1;