diff --git a/debian/control b/debian/control
index 8917b97..ef300ac 100644
--- a/debian/control
+++ b/debian/control
@@ -1,37 +1,38 @@
 Source: swh-loader-mercurial
 Maintainer: Software Heritage developers <swh-devel@inria.fr>
 Section: python
 Priority: optional
 Build-Depends: debhelper (>= 9),
                dh-python (>= 2),
                python3-all,
+               python3-click,
                python3-dateutil,
                python3-nose,
                python3-setuptools,
                python3-vcversioner,
                python3-retrying,
                python3-hglib,
                patool,
                python3-swh.core (>= 0.0.36~),
                python3-swh.model (>= 0.0.27~),
                python3-swh.storage (>= 0.0.95~),
                python3-swh.scheduler (>= 0.0.19~),
                python3-swh.loader.core (>= 0.0.33~),
                python-sqlitedict
 Standards-Version: 3.9.6
 Homepage: https://forge.softwareheritage.org/source/swh-loader-mercurial/
 
 Package: python3-swh.loader.mercurial
 Architecture: all
 Depends: python3-swh.core (>= 0.0.36~),
          python3-swh.loader.core (>= 0.0.33~),
          python3-swh.model (>= 0.0.27~),
          python3-swh.storage (>= 0.0.95~),
          python3-swh.scheduler (>= 0.0.19~),
          patool,
          python-sqlitedict,
          python3-hglib,
          ${misc:Depends}, ${python3:Depends}
 Description: Software Heritage Mercurial Loader
   Module in charge of loading hg/mercurial repositories into
   swh storage.
diff --git a/requirements.txt b/requirements.txt
index 1a1c18f..3e8c649 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,9 +1,10 @@
 # Add here external Python modules dependencies, one per line. Module names
 # should match https://pypi.python.org/pypi names. For the full spec or
 # dependency lines, see https://pip.readthedocs.org/en/1.1/requirements.html
+click
 patool
 python-dateutil
 python-hglib
 retrying
 sqlitedict
 vcversioner
diff --git a/swh/loader/mercurial/cli.py b/swh/loader/mercurial/cli.py
index ae4e3f7..0d32e19 100644
--- a/swh/loader/mercurial/cli.py
+++ b/swh/loader/mercurial/cli.py
@@ -1,48 +1,51 @@
 # Copyright (C) 2018  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 datetime
 import click
+import datetime
 import logging
 
-LOGLEVELS = [logging._levelToName[lvl]
-             for lvl in sorted(logging._levelToName.keys())]
+from itertools import chain
+
+LOGLEVELS = list(chain.from_iterable((logging._levelToName[lvl],
+                                      logging._levelToName[lvl].lower())
+                 for lvl in sorted(logging._levelToName.keys())))
 
 
 @click.command()
 @click.argument('origin-url')
 @click.option('--hg-directory', '-d',
               help=('Path to the hg (local) directory to load from. '
                     'If unset, the hg repo will be cloned from the '
                     'given (origin) url.'))
 @click.option('--hg-archive', '-a',
               help=('Path to the hg archive file to load from.'))
 @click.option('--visit-date', '-D', help='Visit date (defaults to now).')
 @click.option('--log-level', '-l',
-              type=click.Choice(LOGLEVELS, case_sensitive=False),
+              type=click.Choice(LOGLEVELS),
               help='Log level.')
 def main(origin_url, hg_directory=None,
          hg_archive=None, visit_date=None, log_level=None):
 
     logging.basicConfig(
         level=(log_level or 'DEBUG').upper(),
         format='%(asctime)s %(process)d %(message)s')
 
     if not visit_date:
         visit_date = datetime.datetime.now(tz=datetime.timezone.utc)
     kwargs = {'visit_date': visit_date,
               'origin_url': origin_url}
     if hg_archive:
         from .loader import HgArchiveBundle20Loader as HgLoader
         kwargs['archive_path'] = hg_archive
     else:
         from .loader import HgBundle20Loader as HgLoader
         kwargs['directory'] = hg_directory
 
     return HgLoader().load(**kwargs)
 
 
 if __name__ == '__main__':
     main()