C# Compiler Bug

gistfile1.cs

using System.Collections.Generic;
using System.Linq;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            new B().Test().Count();
        }
    }

    class A<T>
    {
        public virtual IEnumerable<T> Test()
        {
            yield return default(T);
        }
    }

    class B : A<int>
    {
        public IEnumerable<int> Test()
        {
            base.Test();
            yield return 0;
        }
    }
}