How to set empty list [] as default value for ArrayAgg field instead of [None] in django

I have a query:

Teacher.objects.alias(
    raw_courses_ids=ArrayAgg('courses_can_teach', distinct=True),
).annotate(
    courses_ids=Case(
        When(raw_courses_ids__contains=[None], then=Value([])),
        default=F('raw_courses_ids'),
        output_field=ArrayField(IntegerField())
    )
).values_list(
    'courses_ids'
)

And I have got an error: django.core.exceptions.FieldError: Cannot resolve expression type, unknown output_field

What I have to do?