Received unregistered task of type, почему не регистрируется таск?

Как вручную добавить таск или настроить автонахождение тасков из других приложений?

Структура проекта


celery.py

# coding: utf8
from __future__ import absolute_import, unicode_literals
import os
from celery import Celery


# set the default Django settings module for the 'celery' program.
os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'backend.settings')

app = Celery('backend')

# Using a string here means the worker doesn't have to serialize
# the configuration object to child processes.
# - namespace='CELERY' means all celery-related configuration keys
#   should have a `CELERY_` prefix.
app.config_from_object('django.conf:settings', namespace='CELERY')

# Load task modules from all registered Django app configs.
app.autodiscover_tasks()

# Redis
app.conf.broker_url = 'redis://redis:6379/0'

@app.task(bind=True)
def debug_task(self):
    print('Request: {0!r}'.format(self.request))


# Celery beat
app.conf.beat_schedule = {
    'scheduled': {
        'task': 'api.controllers.message.scheduled_message',
        'schedule': 60.0
    },
    'collection_of_statics': {
        'task': 'stats.views.collect_stats',
        'schedule': 60.0
    }
}

app.conf.timezone = 'UTC'

backend/__init__.py

from __future__ import absolute_import, unicode_literals

# This will make sure the app is always imported when
# Django starts so that shared_task will use this app.
from .celery import app as celery_app

__all__ = ['celery_app']

settings.py

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'api',
    'stats',
    'corsheaders',
]

Зарегистрированные таски

flower_1     | [I 180221 09:28:27 command:147] Registered tasks:
flower_1     |     ['CallbackNotifier',
flower_1     |      'FB posting',
flower_1     |      'FB token status',
flower_1     |      'MD posting',
flower_1     |      'MD token status',
flower_1     |      'OK posting',
flower_1     |      'OK token status',
flower_1     |      'TW posting',
flower_1     |      'TW token status',
flower_1     |      'VK posting',
flower_1     |      'VK token status',
flower_1     |      'api.controllers.message.scheduled_message',
flower_1     |      'backend.celery.debug_task',
flower_1     |      'celery.accumulate',
flower_1     |      'celery.backend_cleanup',
flower_1     |      'celery.chain',
flower_1     |      'celery.chord',
flower_1     |      'celery.chord_unlock',
flower_1     |      'celery.chunks',
flower_1     |      'celery.group',
flower_1     |      'celery.map',
flower_1     |      'celery.starmap']

Таски, которые находятся в приложении api находит без проблем, с приложения stats не подтягивает

Пробовал добавить в settings.py
CELERY_IMPORTS = ('stats.views')

Таск, который нужно добавить с stats.views

@task()
    def collect_stats():

Какое решение посоветуете?