How to return Boolean values from Perl dancer

dancer.pl

# perl dancer includes JSON::XS
# so returning JSON::XS:

# to return true, JSON::XS::true
get '/works' => {
    return to_json {success => JSON::XS::true};
}

Response:
---------
{
"success": true
}

# to return false, JSON::XS::false
get '/works' => {
    return to_json {success => JSON::XS::false};
}

Response:
---------
{
"success": false
}