diff --git a/swh/lister/bitbucket/tasks.py b/swh/lister/bitbucket/tasks.py
index b8fa316..28b29d6 100644
--- a/swh/lister/bitbucket/tasks.py
+++ b/swh/lister/bitbucket/tasks.py
@@ -1,54 +1,52 @@
 # Copyright (C) 2017-2019 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import random
-from celery import group
-
-from swh.scheduler.celery_backend.config import app
+from celery import group, shared_task
 
 from .lister import BitBucketLister
 
 GROUP_SPLIT = 10000
 
 
-@app.task(name=__name__ + '.IncrementalBitBucketLister')
+@shared_task(name=__name__ + '.IncrementalBitBucketLister')
 def list_bitbucket_incremental(**lister_args):
     '''Incremental update of the BitBucket forge'''
     lister = BitBucketLister(**lister_args)
     lister.run(min_bound=lister.db_last_index(), max_bound=None)
 
 
-@app.task(name=__name__ + '.RangeBitBucketLister')
+@shared_task(name=__name__ + '.RangeBitBucketLister')
 def _range_bitbucket_lister(start, end, **lister_args):
     lister = BitBucketLister(**lister_args)
     lister.run(min_bound=start, max_bound=end)
 
 
-@app.task(name=__name__ + '.FullBitBucketRelister', bind=True)
+@shared_task(name=__name__ + '.FullBitBucketRelister', bind=True)
 def list_bitbucket_full(self, split=None, **lister_args):
     """Full update of the BitBucket forge
 
     It's not to be called for an initial listing.
 
     """
     lister = BitBucketLister(**lister_args)
     ranges = lister.db_partition_indices(split or GROUP_SPLIT)
     if not ranges:
         self.log.info('Nothing to list')
         return
 
     random.shuffle(ranges)
     promise = group(_range_bitbucket_lister.s(minv, maxv, **lister_args)
                     for minv, maxv in ranges)()
     self.log.debug('%s OK (spawned %s subtasks)', (self.name, len(ranges)))
     try:
         promise.save()  # so that we can restore the GroupResult in tests
     except (NotImplementedError, AttributeError):
         self.log.info('Unable to call save_group with current result backend.')
     return promise.id
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/cgit/tasks.py b/swh/lister/cgit/tasks.py
index 0066cf7..1295248 100644
--- a/swh/lister/cgit/tasks.py
+++ b/swh/lister/cgit/tasks.py
@@ -1,18 +1,18 @@
 # Copyright (C) 2019 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from swh.scheduler.celery_backend.config import app
+from celery import shared_task
 
 from .lister import CGitLister
 
 
-@app.task(name=__name__ + '.CGitListerTask')
+@shared_task(name=__name__ + '.CGitListerTask')
 def list_cgit(**lister_args):
     '''Lister task for CGit instances'''
     CGitLister(**lister_args).run()
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/cran/tasks.py b/swh/lister/cran/tasks.py
index 3b449de..6802619 100644
--- a/swh/lister/cran/tasks.py
+++ b/swh/lister/cran/tasks.py
@@ -1,18 +1,18 @@
 # Copyright (C) 2019 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from swh.scheduler.celery_backend.config import app
+from celery import shared_task
 
 from swh.lister.cran.lister import CRANLister
 
 
-@app.task(name=__name__ + '.CRANListerTask')
+@shared_task(name=__name__ + '.CRANListerTask')
 def list_cran(**lister_args):
     '''Lister task for the CRAN registry'''
     CRANLister(**lister_args).run()
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/debian/tasks.py b/swh/lister/debian/tasks.py
index 356b192..ad45f4c 100644
--- a/swh/lister/debian/tasks.py
+++ b/swh/lister/debian/tasks.py
@@ -1,18 +1,18 @@
 # Copyright (C) 2017-2018 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from swh.scheduler.celery_backend.config import app
+from celery import shared_task
 
 from .lister import DebianLister
 
 
-@app.task(name=__name__ + '.DebianListerTask')
+@shared_task(name=__name__ + '.DebianListerTask')
 def list_debian_distribution(distribution, **lister_args):
     '''List a Debian distribution'''
     DebianLister(**lister_args).run(distribution)
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/github/tasks.py b/swh/lister/github/tasks.py
index 555dc0a..207ddf9 100644
--- a/swh/lister/github/tasks.py
+++ b/swh/lister/github/tasks.py
@@ -1,53 +1,52 @@
 # Copyright (C) 2017-2019 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import random
 
-from celery import group
-from swh.scheduler.celery_backend.config import app
+from celery import group, shared_task
 
 from swh.lister.github.lister import GitHubLister
 
 GROUP_SPLIT = 10000
 
 
-@app.task(name=__name__ + '.IncrementalGitHubLister')
+@shared_task(name=__name__ + '.IncrementalGitHubLister')
 def list_github_incremental(**lister_args):
     'Incremental update of GitHub'
     lister = GitHubLister(**lister_args)
     lister.run(min_bound=lister.db_last_index(), max_bound=None)
 
 
-@app.task(name=__name__ + '.RangeGitHubLister')
+@shared_task(name=__name__ + '.RangeGitHubLister')
 def _range_github_lister(start, end, **lister_args):
     lister = GitHubLister(**lister_args)
     lister.run(min_bound=start, max_bound=end)
 
 
-@app.task(name=__name__ + '.FullGitHubRelister', bind=True)
+@shared_task(name=__name__ + '.FullGitHubRelister', bind=True)
 def list_github_full(self, split=None, **lister_args):
     """Full update of GitHub
 
     It's not to be called for an initial listing.
 
     """
     lister = GitHubLister(**lister_args)
     ranges = lister.db_partition_indices(split or GROUP_SPLIT)
     if not ranges:
         self.log.info('Nothing to list')
         return
     random.shuffle(ranges)
     promise = group(_range_github_lister.s(minv, maxv, **lister_args)
                     for minv, maxv in ranges)()
     self.log.debug('%s OK (spawned %s subtasks)' % (self.name, len(ranges)))
     try:
         promise.save()  # so that we can restore the GroupResult in tests
     except (NotImplementedError, AttributeError):
         self.log.info('Unable to call save_group with current result backend.')
     return promise.id
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/gitlab/tasks.py b/swh/lister/gitlab/tasks.py
index 30cab41..bdb23cd 100644
--- a/swh/lister/gitlab/tasks.py
+++ b/swh/lister/gitlab/tasks.py
@@ -1,52 +1,51 @@
 # Copyright (C) 2018 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import random
 
-from celery import group
-from swh.scheduler.celery_backend.config import app
+from celery import group, shared_task
 
 from .. import utils
 from .lister import GitLabLister
 
 
 NBPAGES = 10
 
 
-@app.task(name=__name__ + '.IncrementalGitLabLister')
+@shared_task(name=__name__ + '.IncrementalGitLabLister')
 def list_gitlab_incremental(**lister_args):
     """Incremental update of a GitLab instance"""
     lister_args['sort'] = 'desc'
     lister = GitLabLister(**lister_args)
     total_pages = lister.get_pages_information()[1]
     # stopping as soon as existing origins for that instance are detected
     lister.run(min_bound=1, max_bound=total_pages, check_existence=True)
 
 
-@app.task(name=__name__ + '.RangeGitLabLister')
+@shared_task(name=__name__ + '.RangeGitLabLister')
 def _range_gitlab_lister(start, end, **lister_args):
     lister = GitLabLister(**lister_args)
     lister.run(min_bound=start, max_bound=end)
 
 
-@app.task(name=__name__ + '.FullGitLabRelister', bind=True)
+@shared_task(name=__name__ + '.FullGitLabRelister', bind=True)
 def list_gitlab_full(self, **lister_args):
     """Full update of a GitLab instance"""
     lister = GitLabLister(**lister_args)
     _, total_pages, _ = lister.get_pages_information()
     ranges = list(utils.split_range(total_pages, NBPAGES))
     random.shuffle(ranges)
     promise = group(_range_gitlab_lister.s(minv, maxv, **lister_args)
                     for minv, maxv in ranges)()
     self.log.debug('%s OK (spawned %s subtasks)' % (self.name, len(ranges)))
     try:
         promise.save()
     except (NotImplementedError, AttributeError):
         self.log.info('Unable to call save_group with current result backend.')
     return promise.id
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/gnu/tasks.py b/swh/lister/gnu/tasks.py
index 7191453..1eb7061 100644
--- a/swh/lister/gnu/tasks.py
+++ b/swh/lister/gnu/tasks.py
@@ -1,18 +1,18 @@
 # Copyright (C) 2019 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from swh.scheduler.celery_backend.config import app
+from celery import shared_task
 
 from .lister import GNULister
 
 
-@app.task(name=__name__ + '.GNUListerTask')
+@shared_task(name=__name__ + '.GNUListerTask')
 def list_gnu_full(**lister_args):
     'List lister for the GNU source code archive'
     GNULister(**lister_args).run()
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/npm/tasks.py b/swh/lister/npm/tasks.py
index 8d1c369..94b991b 100644
--- a/swh/lister/npm/tasks.py
+++ b/swh/lister/npm/tasks.py
@@ -1,62 +1,62 @@
 # Copyright (C) 2018 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 from datetime import datetime
 from contextlib import contextmanager
 
-from swh.scheduler.celery_backend.config import app
+from celery import shared_task
 
 from swh.lister.npm.lister import NpmLister, NpmIncrementalLister
 from swh.lister.npm.models import NpmVisitModel
 
 
 @contextmanager
 def save_registry_state(lister):
     params = {'headers': lister.request_headers()}
     registry_state = lister.session.get(lister.url, **params)
     registry_state = registry_state.json()
     keys = ('doc_count', 'doc_del_count', 'update_seq', 'purge_seq',
             'disk_size', 'data_size', 'committed_update_seq',
             'compacted_seq')
 
     state = {key: registry_state[key] for key in keys}
     state['visit_date'] = datetime.now()
     yield
     npm_visit = NpmVisitModel(**state)
     lister.db_session.add(npm_visit)
     lister.db_session.commit()
 
 
 def get_last_update_seq(lister):
     """Get latest ``update_seq`` value for listing only updated packages.
     """
     query = lister.db_session.query(NpmVisitModel.update_seq)
     row = query.order_by(NpmVisitModel.uid.desc()).first()
     if not row:
         raise ValueError('No npm registry listing previously performed ! '
                          'This is required prior to the execution of an '
                          'incremental listing.')
     return row[0]
 
 
-@app.task(name=__name__ + '.NpmListerTask')
+@shared_task(name=__name__ + '.NpmListerTask')
 def list_npm_full(**lister_args):
     'Full lister for the npm (javascript) registry'
     lister = NpmLister(**lister_args)
     with save_registry_state(lister):
         lister.run()
 
 
-@app.task(name=__name__ + '.NpmIncrementalListerTask')
+@shared_task(name=__name__ + '.NpmIncrementalListerTask')
 def list_npm_incremental(**lister_args):
     'Incremental lister for the npm (javascript) registry'
     lister = NpmIncrementalLister(**lister_args)
     update_seq_start = get_last_update_seq(lister)
     with save_registry_state(lister):
         lister.run(min_bound=update_seq_start)
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/packagist/tasks.py b/swh/lister/packagist/tasks.py
index 6db17dc..146ebe2 100644
--- a/swh/lister/packagist/tasks.py
+++ b/swh/lister/packagist/tasks.py
@@ -1,18 +1,18 @@
 # Copyright (C) 2019 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from swh.scheduler.celery_backend.config import app
+from celery import shared_task
 
 from .lister import PackagistLister
 
 
-@app.task(name=__name__ + '.PackagistListerTask')
+@shared_task(name=__name__ + '.PackagistListerTask')
 def list_packagist(**lister_args):
     'List the packagist (php) registry'
     PackagistLister(**lister_args).run()
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/phabricator/tasks.py b/swh/lister/phabricator/tasks.py
index 0b8b77d..361fedd 100644
--- a/swh/lister/phabricator/tasks.py
+++ b/swh/lister/phabricator/tasks.py
@@ -1,17 +1,18 @@
 # Copyright (C) 2019 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from swh.scheduler.celery_backend.config import app
+from celery import shared_task
+
 from swh.lister.phabricator.lister import PhabricatorLister
 
 
-@app.task(name=__name__ + '.FullPhabricatorLister')
+@shared_task(name=__name__ + '.FullPhabricatorLister')
 def list_phabricator_full(**lister_args):
     'Full update of a Phabricator instance'
     PhabricatorLister(**lister_args).run()
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'
diff --git a/swh/lister/pypi/tasks.py b/swh/lister/pypi/tasks.py
index d6206a4..2412f26 100644
--- a/swh/lister/pypi/tasks.py
+++ b/swh/lister/pypi/tasks.py
@@ -1,18 +1,18 @@
 # Copyright (C) 2018 the Software Heritage developers
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
-from swh.scheduler.celery_backend.config import app
+from celery import shared_task
 
 from .lister import PyPILister
 
 
-@app.task(name=__name__ + '.PyPIListerTask')
+@shared_task(name=__name__ + '.PyPIListerTask')
 def list_pypi(**lister_args):
     'Full update of the PyPI (python) registry'
     PyPILister(**lister_args).run()
 
 
-@app.task(name=__name__ + '.ping')
+@shared_task(name=__name__ + '.ping')
 def _ping():
     return 'OK'