diff --git a/swh/scanner/cli.py b/swh/scanner/cli.py
index 74805b2..93a27c0 100644
--- a/swh/scanner/cli.py
+++ b/swh/scanner/cli.py
@@ -1,113 +1,127 @@
 # Copyright (C) 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 os
 from typing import Any, Dict, Optional
 
 import click
+import yaml
 
 from swh.core import config
 from swh.core.cli import CONTEXT_SETTINGS
 from swh.core.cli import swh as swh_cli_group
 
 # All generic config code should reside in swh.core.config
-DEFAULT_CONFIG_PATH = os.environ.get(
-    "SWH_CONFIG_FILE", os.path.join(click.get_app_dir("swh"), "global.yml")
-)
-
+CONFIG_ENVVAR = "SWH_CONFIG_FILE"
+DEFAULT_CONFIG_PATH = os.path.join(click.get_app_dir("swh"), "global.yml")
+DEFAULT_PATH = os.environ.get(CONFIG_ENVVAR, DEFAULT_CONFIG_PATH)
 
 DEFAULT_CONFIG: Dict[str, Any] = {
     "web-api": {
         "url": "https://archive.softwareheritage.org/api/1/",
         "auth-token": None,
     }
 }
 
 
-@swh_cli_group.group(name="scanner", context_settings=CONTEXT_SETTINGS)
+CONFIG_FILE_HELP = f"""Configuration file:
+
+\b
+The CLI option or the environment variable will fail if invalid.
+CLI option is checked first.
+Then, environment variable {CONFIG_ENVVAR} is checked.
+Then, if cannot load the default path, a set of default values are used.
+Default config path is {DEFAULT_CONFIG_PATH}.
+Default config values are:
+
+\b
+{yaml.dump(DEFAULT_CONFIG)}"""
+SCANNER_HELP = f"""Software Heritage Scanner tools.
+
+{CONFIG_FILE_HELP}"""
+
+
+@swh_cli_group.group(
+    name="scanner", context_settings=CONTEXT_SETTINGS, help=SCANNER_HELP,
+)
 @click.option(
     "-C",
     "--config-file",
     default=None,
     type=click.Path(exists=False, dir_okay=False, path_type=str),
-    help=f"""YAML configuration file. If absent and cannot load the default one,
-    default parameters are used.
-    Default config path is {DEFAULT_CONFIG_PATH}.
-    Default config values are {DEFAULT_CONFIG}
-    """,
+    help="""YAML configuration file""",
 )
 @click.pass_context
 def scanner(ctx, config_file: Optional[str]):
-    """Software Heritage Scanner tools."""
-    if config_file is None and config.config_exists(DEFAULT_CONFIG_PATH):
-        config_file = DEFAULT_CONFIG_PATH
+    if config_file is None and config.config_exists(DEFAULT_PATH):
+        config_file = DEFAULT_PATH
 
     if config_file is None:
         conf = DEFAULT_CONFIG
     else:
         # read_raw_config do not fail on ENOENT
         if not config.config_exists(config_file):
             raise FileNotFoundError(config_file)
         conf = config.read_raw_config(config.config_basepath(config_file))
         conf = config.merge_configs(DEFAULT_CONFIG, conf)
 
     ctx.ensure_object(dict)
     ctx.obj["config"] = conf
 
 
 @scanner.command(name="scan")
 @click.argument("root_path", required=True, type=click.Path(exists=True))
 @click.option(
     "-u",
     "--api-url",
     default=None,
     metavar="API_URL",
     show_default=True,
     help="URL for the api request",
 )
 @click.option(
     "--exclude",
     "-x",
     "patterns",
     metavar="PATTERN",
     multiple=True,
     help="Exclude directories using glob patterns \
     (e.g., '*.git' to exclude all .git directories)",
 )
 @click.option(
     "-f",
     "--output-format",
     "out_fmt",
     default="text",
     show_default=True,
     type=click.Choice(["text", "json", "ndjson", "sunburst"], case_sensitive=False),
     help="The output format",
 )
 @click.option(
     "-i", "--interactive", is_flag=True, help="Show the result in a dashboard"
 )
 @click.pass_context
 def scan(ctx, root_path, api_url, patterns, out_fmt, interactive):
     """Scan a source code project to discover files and directories already
     present in the archive"""
     from .scanner import scan
 
     config = ctx.obj["config"]
     if api_url:
         if not api_url.endswith("/"):
             api_url += "/"
         config["web-api"]["url"] = api_url
 
     scan(config, root_path, patterns, out_fmt, interactive)
 
 
 def main():
     return scanner(auto_envvar_prefix="SWH_SCANNER")
 
 
 if __name__ == "__main__":
     main()