Rendering Html.Hidden helper with custom value
===

I have the following razor markup:

    @{
        var initValue = @Html.Raw(new JavaScriptSerializer().Serialize(Model));
        @Html.Hidden("initial-namings-data", initValue.ToString());
    }

It gives me error:

    'System.Web.Mvc.HtmlHelper' has no applicable method named 'Hidden' but appears to have an extension method by that name. Extension methods cannot be dynamically dispatched. Consider casting the dynamic arguments or calling the extension method without the extension method syntax.

How can I fix it? Thanks.