Since the container ABCs are normal classes, and Protocol cannot subclass normal classes, there's no way to create a protocol that extends the ABCs without explicitly listing out all the methods needed for the collection. e.g., can't do this: from typing import Iterable, Protocol class IterableWithMethod(Iterable, Protocol): def method(self) -> None: pass Since the ABCs don't provide any default implementations (I think?), maybe they should just be defined as runtime checkable protocols instead of ABCs?