I want to use abstractmethod, but I have my own metaclasses and I don't want to build composite metaclasses using abc.ABCMeta. Thanks to PEP 487, one approach is to facator out the abstractmethod checks from ABCMeta into a regular (non-meta) class. So, my first suggestion is to split abc.ABC into two pieces, a parent regular class with metaclass "type": class AbstractBaseClass: def __init_subclass__(cls): # Compute set of abstract method names abstracts = {name for name, value in vars(cls).items() if getattr(value, "__isabstractmethod__", False)} for base in cls.__bases__: for name in getattr(base, "__abstractmethods__", set()): value = getattr(cls, name, None) if getattr(value, "__isabstractmethod__", False): abstracts.add(name) cls.__abstractmethods__ = frozenset(abstracts) My alternative suggestion is to move this logic directly into "type" so that all classes have this logic, and then move abstractmethod into builtins. Of course, this isn't pressing since I can do this in my own code, it's just a suggestion from a neatness standpoint. Best, Neil