diff --git a/swh/loader/tar/producer.py b/swh/loader/tar/producer.py
index e692b7f..a13765c 100755
--- a/swh/loader/tar/producer.py
+++ b/swh/loader/tar/producer.py
@@ -1,101 +1,101 @@
 # Copyright (C) 2015-2017  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 click
 import dateutil.parser
 
 from swh.scheduler.utils import get_task
 
 from swh.core import config
 from swh.loader.tar import build, file
 
 
 TASK_QUEUE = 'swh.loader.tar.tasks.LoadTarRepository'
 
 
 def produce_archive_messages_from(
         conf, root_dir, visit_date, mirror_file=None, dry_run=False):
     """From root_dir, produce archive tarball messages to celery.
 
     Will print error message when some computation arise on archive
     and continue.
 
     Args:
         conf: dictionary holding static metadata
         root_dir: top directory to list archives from.
         visit_date: override origin's visit date of information
         mirror_file: a filtering file of tarballs to load
         dry_run: will compute but not send messages
 
     Returns:
         Number of messages generated
 
     """
 
-    limit = conf['limit']
+    limit = conf.get('limit')
     block = int(conf['block_messages'])
     count = 0
 
     path_source_tarballs = mirror_file if mirror_file else root_dir
 
     visit_date = dateutil.parser.parse(visit_date)
     if not dry_run:
         task = get_task(TASK_QUEUE)
 
     for tarpath, _ in file.random_archives_from(
             path_source_tarballs, block, limit):
         try:
             origin = build.compute_origin(
                 conf['url_scheme'], conf['type'], root_dir, tarpath)
             revision = build.compute_revision(tarpath)
             occurrence = build.compute_occurrence(tarpath)
 
             if not dry_run:
                 task.delay(tarpath, origin, visit_date, revision, [occurrence])
 
             count += 1
         except ValueError:
             print('Problem with the following archive: %s' % tarpath)
 
     return count
 
 
 @click.command()
 @click.option('--config-file', required=1,
               help='Configuration file path')
 @click.option('--dry-run/--no-dry-run', default=False,
               help='Dry run (print repo only)')
 @click.option('--limit', default=None,
               help='Number of origins limit to send')
 def main(config_file, dry_run, limit):
     """Tarball producer of local fs tarballs.
 
     """
     conf = config.read(config_file)
     url_scheme = conf['url_scheme']
     mirror_dir = conf['mirror_root_directory']
 
     # remove trailing / in configuration (to ease ulterior computation)
     if url_scheme[-1] == '/':
         conf['url_scheme'] = url_scheme[0:-1]
 
     if mirror_dir[-1] == '/':
         conf['mirror_root_directory'] = mirror_dir[0:-1]
 
     if limit:
         conf['limit'] = int(limit)
 
     nb_tarballs = produce_archive_messages_from(
         conf=conf,
         root_dir=conf['mirror_root_directory'],
         visit_date=conf['date'],
         mirror_file=conf.get('mirror_subset_archives'),
         dry_run=dry_run)
 
     print('%s tarball(s) sent to worker.' % nb_tarballs)
 
 
 if __name__ == '__main__':
     main()