Possible issue with Sinon.JS with child properties of stubbed functions

gistfile1.js

var MyClass = function(myVar)
{
    // example constructor
    this.myVar = myVar;
}
			
MyClass.MyNamespacedClass = function()
{
    // could be any property, not necessarily a function
}
			
console.log(typeof MyClass.MyNamespacedClass); // "function"
			
var myClassStub = sinon.stub(window, "MyClass");
			
console.log(typeof MyClass.MyNamespacedClass); // "undefined"