Possible bugs could be hidden behind the use of $.extend when we merge DT's options. We are using (almost everywhere): $(selector).dataTable($.extend(true, {}, dataTablesDefaults, { But: var dataTablesDefaults = { "lengthMenu": [[10, 20, 50, 100, -1], [10, 20, 50, 100, __('All')]] }; var mine = {lengthMenu: [[1, 2, 5, 10], [1, 2, 5, 10]]}; $.extend(true, {}, dataTablesDefaults, mine); [ 1, 2, 5, 10, -1 ] See also bug 30397.