Send list/array as parameter with jQuery getJson

I have the following where I'm trying to send list/array to MVC controller method:

var id = [];
var inStock = [];

$table.find('tbody>tr').each(function() {
    id.push($(this).find('.id').text());
    inStock.push($(this).find('.stocked').attr('checked'));
});

var params = {};
params.ids = id;
params.stocked = inStock; 

$.getJSON('MyApp/UpdateStockList', params, function() {
    alert('finished');
});    

in my contoller:

public JsonResult UpdateStockList(int[] ids, bool[] stocked) { }

both paramaters are null.

Note that if I change the params to single items

params.ids = 1;
params.stocked = true; 

public JsonResult UpdateStockList(int ids, bool stocked) { }

then it works ok, so I don't think it's a routing issue.