diff --git a/swh/objstorage/cli.py b/swh/objstorage/cli.py
index 3180b88..5eff218 100644
--- a/swh/objstorage/cli.py
+++ b/swh/objstorage/cli.py
@@ -1,130 +1,131 @@
 # Copyright (C) 2015-2020  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
 
 # WARNING: do not import unnecessary things here to keep cli startup time under
 # control
 import os
 import time
 
 import click
 
-from swh.core.cli import CONTEXT_SETTINGS, swh as swh_cli_group
+from swh.core.cli import CONTEXT_SETTINGS
+from swh.core.cli import swh as swh_cli_group
 
 
 @swh_cli_group.group(name="objstorage", context_settings=CONTEXT_SETTINGS)
 @click.option(
     "--config-file",
     "-C",
     default=None,
     type=click.Path(exists=True, dir_okay=False,),
     help="Configuration file.",
 )
 @click.pass_context
 def objstorage_cli_group(ctx, config_file):
     """Software Heritage Objstorage tools.
     """
     from swh.core import config
 
     if not config_file:
         config_file = os.environ.get("SWH_CONFIG_FILENAME")
 
     if config_file:
         if not os.path.exists(config_file):
             raise ValueError("%s does not exist" % config_file)
         conf = config.read(config_file)
     else:
         conf = {}
 
     ctx.ensure_object(dict)
 
     ctx.obj["config"] = conf
 
 
 # for BW compat
 cli = objstorage_cli_group
 
 
 @objstorage_cli_group.command("rpc-serve")
 @click.option(
     "--host",
     default="0.0.0.0",
     metavar="IP",
     show_default=True,
     help="Host ip address to bind the server on",
 )
 @click.option(
     "--port",
     "-p",
     default=5003,
     type=click.INT,
     metavar="PORT",
     show_default=True,
     help="Binding port of the server",
 )
 @click.pass_context
 def serve(ctx, host, port):
     """Run a standalone objstorage server.
 
     This is not meant to be run on production systems.
     """
     import aiohttp.web
 
     from swh.objstorage.api.server import make_app, validate_config
 
     app = make_app(validate_config(ctx.obj["config"]))
     if ctx.obj["log_level"] == "DEBUG":
         app.update(debug=True)
     aiohttp.web.run_app(app, host=host, port=int(port))
 
 
 @objstorage_cli_group.command("import")
 @click.argument("directory", required=True, nargs=-1)
 @click.pass_context
 def import_directories(ctx, directory):
     """Import a local directory in an existing objstorage.
     """
     from swh.objstorage.factory import get_objstorage
 
     objstorage = get_objstorage(**ctx.obj["config"]["objstorage"])
     nobj = 0
     volume = 0
     t0 = time.time()
     for dirname in directory:
         for root, _dirs, files in os.walk(dirname):
             for name in files:
                 path = os.path.join(root, name)
                 with open(path, "rb") as f:
                     objstorage.add(f.read())
                     volume += os.stat(path).st_size
                     nobj += 1
     click.echo(
         "Imported %d files for a volume of %s bytes in %d seconds"
         % (nobj, volume, time.time() - t0)
     )
 
 
 @objstorage_cli_group.command("fsck")
 @click.pass_context
 def fsck(ctx):
     """Check the objstorage is not corrupted.
     """
     from swh.objstorage.factory import get_objstorage
 
     objstorage = get_objstorage(**ctx.obj["config"]["objstorage"])
     for obj_id in objstorage:
         try:
             objstorage.check(obj_id)
         except objstorage.Error as err:
             logging.error(err)
 
 
 def main():
     return cli(auto_envvar_prefix="SWH_OBJSTORAGE")
 
 
 if __name__ == "__main__":
     main()