Validating Boolean Values

Using WebApi 2, I have a model that contains a Boolean value:

[Display(Name = "notify")]
[DataMember]
public bool notify
        { get; set; }

The input format is JSON.  ModelState will reject any value other than lower case "true" / "false."   Therefore, if a user sends in "FALSE" or "False" or "1" then there is a fail.  Is there a noted way to accept these values without 1) changing the "notify" field to string and 2) without having to write custom code?

Thanks,

cj