namespace DynamicTesting

{

    public interface IDynamicTargetBase

    {

        string Hello(int a);

    }

​

    public interface IDynamicTarget : IDynamicTargetBase

    {

    }

​

    public class DynamicTarget : IDynamicTarget

    {

        public string Hello(int a)

        {

            return "Hello!";

        }

    }

​

    public class Program

    {

        public static void Main(string[] args)

        {

            dynamic a = 123;

​

            IDynamicTargetBase obj1 = new DynamicTarget();

            obj1.Hello(a);  // This works just fine

​

            IDynamicTarget obj2 = new DynamicTarget();

            obj2.Hello(a); // RuntimeBinderException "No overload for method 'Hello' takes '1' arguments"

        }

    }

}