diff --git a/debian/control b/debian/control
index 2fa13a3..c1f73d4 100644
--- a/debian/control
+++ b/debian/control
@@ -1,21 +1,20 @@
 Source: swh-core
 Maintainer: Software Heritage developers <swh-devel@inria.fr>
 Section: python
 Priority: optional
 Build-Depends: debhelper (>= 9),
                dh-python,
                python3-all,
-               python3-celery,
                python3-dateutil,
                python3-msgpack,
                python3-nose,
                python3-psycopg2,
                python3-setuptools,
                python3-vcversioner
 Standards-Version: 3.9.6
 Homepage: https://forge.softwareheritage.org/diffusion/DCORE/
 
 Package: python3-swh.core
 Architecture: all
 Depends: ${misc:Depends}, ${python3:Depends}
 Description: Software Heritage core utilities
diff --git a/swh/core/logger.py b/swh/core/logger.py
index 69000ad..8dc08a2 100644
--- a/swh/core/logger.py
+++ b/swh/core/logger.py
@@ -1,98 +1,102 @@
 # Copyright (C) 2015  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 import logging
 import os
 import psycopg2
 import socket
 
-from celery import current_task
+try:
+    from celery import current_task
+except ImportError:
+    current_task = None
+
 from psycopg2.extras import Json
 
 
 EXTRA_LOGDATA_PREFIX = 'swh_'
 
 
 def db_level_of_py_level(lvl):
     """convert a log level of the logging module to a log level suitable for the
     logging Postgres DB
 
     """
     return logging.getLevelName(lvl).lower()
 
 
 class PostgresHandler(logging.Handler):
     """log handler that store messages in a Postgres DB
 
     See swh-core/sql/log-schema.sql for the DB schema.
 
     All logging methods can be used as usual. Additionally, arbitrary metadata
     can be passed to logging methods, requesting that they will be stored in
     the DB as a single JSONB value. To do so, pass a dictionary to the 'extra'
     kwarg of any logging method; all keys in that dictionary that start with
     EXTRA_LOGDATA_PREFIX (currently: 'swh_') will be extracted to form the
     JSONB dictionary. The prefix will be stripped and not included in the DB.
 
     Note: the logger name will be used to fill the 'module' DB column.
 
     Sample usage:
 
         logging.basicConfig(level=logging.INFO)
         h = PostgresHandler('dbname=softwareheritage-log')
         logging.getLogger().addHandler(h)
 
         logger.info('not so important notice',
                     extra={'swh_type': 'swh_logging_test',
                            'swh_meditation': 'guru'})
         logger.warn('something weird just happened, did you see that?')
 
     """
 
     def __init__(self, connstring):
         """
         Create a Postgres log handler.
 
         Args:
             config: configuration dictionary, with a key "log_db" containing a
                libpq connection string to the log DB
         """
         super().__init__()
 
         self.connstring = connstring
 
         self.fqdn = socket.getfqdn()  # cache FQDN value
 
     def _connect(self):
         return psycopg2.connect(self.connstring)
 
     def emit(self, record):
         log_data = record.__dict__
 
         msg = self.format(record)
 
         extra_data = {k[len(EXTRA_LOGDATA_PREFIX):]: v
                       for k, v in log_data.items()
                       if k.startswith(EXTRA_LOGDATA_PREFIX)}
 
         # Retrieve Celery task info
         if current_task and current_task.request:
             extra_data['task'] = {
                 'id': current_task.request.id,
                 'name': current_task.name,
                 'kwargs': current_task.request.kwargs,
                 'args': current_task.request.args,
             }
 
         log_entry = (db_level_of_py_level(log_data['levelno']), msg,
                      Json(extra_data), log_data['name'], self.fqdn,
                      os.getpid())
         db = self._connect()
         with db.cursor() as cur:
             cur.execute('INSERT INTO log '
                         '(level, message, data, src_module, src_host, src_pid)'
                         'VALUES (%s, %s, %s, %s, %s, %s)',
                         log_entry)
             db.commit()
         db.close()