diff --git a/swh/icinga_plugins/cli.py b/swh/icinga_plugins/cli.py
index 08b437d..baaf15f 100644
--- a/swh/icinga_plugins/cli.py
+++ b/swh/icinga_plugins/cli.py
@@ -1,80 +1,82 @@
-# Copyright (C) 2019  The Software Heritage developers
+# Copyright (C) 2019-2020  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
 
+# WARNING: do not import unnecessary things here to keep cli startup time under
+# control
 import sys
 
 import click
 
 from swh.core.cli import CONTEXT_SETTINGS
 
-from .deposit import DepositCheck
-from .vault import VaultCheck
-
 
 @click.group(name='icinga_plugins', context_settings=CONTEXT_SETTINGS)
 @click.option('-w', '--warning', type=int,
               help='Warning threshold.')
 @click.option('-c', '--critical', type=int,
               help='Critical threshold.')
 @click.pass_context
 def cli(ctx, warning, critical):
     """Main command for Icinga plugins
     """
     ctx.ensure_object(dict)
     if warning:
         ctx.obj['warning_threshold'] = int(warning)
     if critical:
         ctx.obj['critical_threshold'] = int(critical)
 
 
 @cli.group(name='check-vault')
 @click.option('--swh-storage-url', type=str, required=True,
               help='URL to an swh-storage HTTP API')
 @click.option('--swh-web-url', type=str, required=True,
               help='URL to an swh-web instance')
 @click.option('--poll-interval', type=int, default=10,
               help='Interval (in seconds) between two polls to the API, '
                    'to check for cooking status.')
 @click.pass_context
 def check_vault(ctx, **kwargs):
     ctx.obj.update(kwargs)
 
 
 @check_vault.command(name='directory')
 @click.pass_context
 def check_vault_directory(ctx):
     """Picks a random directory, requests its cooking via swh-web,
     and waits for completion."""
+    from .vault import VaultCheck
     sys.exit(VaultCheck(ctx.obj).main())
 
 
 @cli.group(name='check-deposit')
 @click.option('--server', type=str,
               default='https://deposit.softwareheritage.org/1',
               help='URL to the SWORD server to test')
 @click.option('--username', type=str, required=True,
               help='Login for the SWORD server')
 @click.option('--password', type=str, required=True,
               help='Password for the SWORD server')
 @click.option('--collection', type=str, required=True,
               help='Software collection to use on the SWORD server')
 @click.option('--poll-interval', type=int, default=10,
               help='Interval (in seconds) between two polls to the API, '
                    'to check for ingestion status.')
 @click.pass_context
 def check_deposit(ctx, **kwargs):
     ctx.obj.update(kwargs)
 
 
 @check_deposit.command(name='single')
 @click.option('--archive', type=click.Path(), required=True,
               help='Software artefact to upload')
 @click.option('--metadata', type=click.Path(), required=True,
               help='Metadata file for the software artefact.')
 @click.pass_context
 def check_deposit_single(ctx, **kwargs):
     """Checks the provided archive and metadata file and be deposited."""
+    from .deposit import DepositCheck
+
     ctx.obj.update(kwargs)
     sys.exit(DepositCheck(ctx.obj).main())