Overriding default adapters in psycopg

Hi!

I am attempting to override the default adapters for JSON and JSONB in psycopg (3), but I am not quite sure how to go
aboutit (I'm testing using orjson for serialization and deserialization).  This doesn't appear to work: 

> class CyanJSONBLoader(Loader):
>     def load(self, data):
>         return orjson.loads(data)
>
> psycopg.adapters.register_loader("jsonb", CyanJSONBLoader)
>
> class CyanJSONBDumper(Dumper):
>     def dump(self, obj):
>         return orjson.dumps(obj)
>
> psycopg.adapters.register_dumper("jsonb", CyanJSONBDumper)
>

The calls work, but the dump/load functions are never called.

Thanks!