Arrays in node-soap

I'm attemping to leverage node-soap to make a SOAP request containing an array. Requests without arrays seem to work fine however when attempting to pass an array I'm receiving the error 'not an ARRAY reference' from the server.

Any idea? My script is as follows:

var soap = require('soap');

var url = 'http://example.com/example.wsdl';

var args = {
    email: 'example',
    password: 'xxxxx',
    series: {
        element: ['a', 'b', 'c', 'd']
    }
};

soap.createClient(url, function(err, client) {
    if(err) throw err;

    client.ExampleMethod(args, function(err, result) {
        if(err) throw err;
        console.log(result);
    });
});