Jquery post to Action with Dictionary Parameter

I am feeling dejavu, but I cannot find the answer to this: I have an array of objects that needs to look like this when inspecting a jQ $.post call:

limiter[0].Key
limiter[0].Value

so that it is mapped in the action

public ActionResult SomeAction(Dictionary<Guid, string> dictionary) { }

However, this javascript:

// Some Guid and Some Value
var param = [ { 'Key' : '00000000-0000-00000-000000', 'Value': 'someValue' } ];

$.post('/SomeController/SomeAction/',
       {
       dictionary: limiter,
       otherPostData: data
       },
       function(data) {
          callback(data);
       }
)

produces this when inspecting it in firebug:

limiter[0][Key] = someKey // Guid Value
limiter[0][Value] = someValue

This is in jq 1.4.2. I seem to remember some flag you need to set to render json a different way in jQ. Does this ring any bells?