Call Method overloaded from abstract class

I need to call a Method of a an abstract class implementation. But the compiler always defaults to use the overloaded method from the concrete class, since the signature just requires an inherited type. Just have a look at the code: -- This is obviously a vastly simplified version of the actual code that I'm using ;) ``` public class ModelBase { } public class ModelA : ModelBase { } public interface IInterface<in TModel> { void Do(TModel model); } public abstract class AbstractClass<TModel> : IInterface<TModel> { public abstract void Do(TModel model); } public class ConcreteClass : AbstractClass<ModelA>, IInterface<ModelBase> { public override void Do(ModelA model) { // I'd like to invoke this method } public void Do(ModelBase model) { // how do I invoke the method above?? Do((ModelA)model); } } ``` ^^ This results in a recursion What I've tried is: ``` ((IClass<ModelA>)this).Do((ModelA)model); ``` ^^ doesn't change anything ``` base.Do((ModelA)model); ``` ^^ throws an error "Cannot call an abstract base member: 'AbstractClass.Do(ModelA)'" How do I call the "public override void Do(ModelA model)" method? btw. If I change the class to this ``` public class ConcreteClass : IInterface<ModelA>, IInterface<ModelBase> ``` it works.