autorest: Anonymous types are not getting properly serialized

The below request gets converted,

var extendedData = new[]
    {                
        new { Name = "foo", Value = 1 },
        new { Name = "bar", Value = 2 },
    };
request.ExtendedData = extendedData;

into following JSON

{"Data":"test","Monitoring":true,"ExtendedData":[{},{}]}

with SafeJsonConvert.SerializeObject. It works as expected with JsonConvert.Serialize method of JSON.NET.