C# Bug: Attribute with nullable parameter and default value

// CSC : error CS0182: An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type

using System;

[AttributeUsage(AttributeTargets.All)]
class MyAttribute : Attribute
{
  public MyAttribute(int? value = null) { }
}

[My]
class Program
{
  static void Main() { }
}