diff --git a/swh/core/cli/__init__.py b/swh/core/cli/__init__.py
index 685f2e2..e60d92b 100644
--- a/swh/core/cli/__init__.py
+++ b/swh/core/cli/__init__.py
@@ -1,111 +1,106 @@
 # Copyright (C) 2019  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 logging.config
 import signal
 
 import click
 import pkg_resources
 import yaml
 
 LOG_LEVEL_NAMES = ['NOTSET', 'DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
 
 CONTEXT_SETTINGS = dict(help_option_names=['-h', '--help'])
 
 logger = logging.getLogger(__name__)
 
 
 class AliasedGroup(click.Group):
     '''A simple Group that supports command aliases, as well as notes related to
     options'''
 
     def __init__(self, name=None, commands=None, **attrs):
         self.option_notes = attrs.pop('option_notes', None)
+        self.aliases = {}
         super().__init__(name, commands, **attrs)
 
-    @property
-    def aliases(self):
-        if not hasattr(self, '_aliases'):
-            self._aliases = {}
-        return self._aliases
-
     def get_command(self, ctx, cmd_name):
         return super().get_command(ctx, self.aliases.get(cmd_name, cmd_name))
 
     def add_alias(self, name, alias):
         if not isinstance(name, str):
             name = name.name
         self.aliases[alias] = name
 
     def format_options(self, ctx, formatter):
         click.Command.format_options(self, ctx, formatter)
         if self.option_notes:
             with formatter.section('Notes'):
                 formatter.write_text(self.option_notes)
         self.format_commands(ctx, formatter)
 
 
 def clean_exit_on_signal(signal, frame):
     """Raise a SystemExit exception to let command-line clients wind themselves
     down on exit"""
     raise SystemExit(0)
 
 
 @click.group(
     context_settings=CONTEXT_SETTINGS, cls=AliasedGroup,
     option_notes='''\
 If both options are present, --log-level will override the root logger
 configuration set in --log-config.
 
 The --log-config YAML must conform to the logging.config.dictConfig schema
 documented at https://docs.python.org/3/library/logging.config.html.
 '''
 )
 @click.option('--log-level', '-l', default=None,
               type=click.Choice(LOG_LEVEL_NAMES),
               help="Log level (defaults to INFO).")
 @click.option('--log-config', default=None,
               type=click.File('r'),
               help="Python yaml logging configuration file.")
 @click.pass_context
 def swh(ctx, log_level, log_config):
     """Command line interface for Software Heritage.
     """
     signal.signal(signal.SIGTERM, clean_exit_on_signal)
     signal.signal(signal.SIGINT, clean_exit_on_signal)
 
     if log_level is None and log_config is None:
         log_level = 'INFO'
 
     if log_config:
         logging.config.dictConfig(yaml.safe_load(log_config.read()))
 
     if log_level:
         log_level = logging.getLevelName(log_level)
         logging.root.setLevel(log_level)
 
     ctx.ensure_object(dict)
     ctx.obj['log_level'] = log_level
 
 
 def main():
     # Even though swh() sets up logging, we need an earlier basic logging setup
     # for the next few logging statements
     logging.basicConfig()
     # load plugins that define cli sub commands
     for entry_point in pkg_resources.iter_entry_points('swh.cli.subcommands'):
         try:
             cmd = entry_point.load()
             swh.add_command(cmd, name=entry_point.name)
         except Exception as e:
             logger.warning('Could not load subcommand %s: %s',
                            entry_point.name, str(e))
 
     return swh(auto_envvar_prefix='SWH')
 
 
 if __name__ == '__main__':
     main()