Java: TBase signature should be T extends TBase<?,?>

Right now TBase looks like:
public interface TBase<T extends TBase, F extends TFieldIdEnum> extends Comparable<T>, Serializable {

but it should be:
public interface TBase<T extends TBase<?,?>, F extends TFieldIdEnum> extends Comparable<T>, Serializable {

While the Java compiler does not have a problem, the Scala compiler throws a fit and refuses to upcast generated classes to 'TBase' when required, such as calling TSerializer.serialize