Validation is a boxing value is default

I very like my lovely extension IsDefault but unpossible to use it where a value is boxing. A cool feature of C#  default(...)  cannot help because a argument required Type. After long research was created small solution:

static bool IsDefault(object o)
{
    if (o == null)
    {
        return true;
    }
    //Check is type os object is ValueType
    if (o.GetType().IsValueType)
    {
        return Activator.CreateInstance(o.GetType()).Equals(o);
    }
    //ReferenceType
    return false;
}

Also can be implemented as extension.