diff --git a/README.md b/README.md
index 570f4f9..4d98869 100644
--- a/README.md
+++ b/README.md
@@ -310,7 +310,7 @@ matched = [ p['name'] for p in output['messages'][-1]['patterns'] if p['matched'
 
 The following options are common to both bots :
 
-- **--config-file** and **--config-dir** let you change the default configuration directory and file. All configuration files will be looked up from this directory ; `--config-file` allows overriding the location of `config.yml`.
+- **--config-file** and **--config-dirs** let you change the default configuration directory and file. All configuration files will be looked up from this directory ; `--config-file` allows overriding the location of `config.yml`.
 - **--backend** selects the *chatter* system to use : it currently supports "console", "signal" and "jabber" (see below)
 - **--stealth** will make the bot connect and listen to messages but print answers to the console instead of sending it ; useful to observe the bot's behavior in a real chatroom...
 - **--debug / -d / --verbosity / -v** those options modify the verbosity level : `--debug` is a flag that sets it to *DEBUG* while with `--verbosity` you can define [the exact level](https://docs.python.org/3/library/logging.html#levels) (e.g. `-v TRACE`).
@@ -320,7 +320,7 @@ The following options are common to both bots :
 #### Configuration file : config.yml
 
 Options can also be taken from a configuration file.
-By default it reads the `config.yml` file in the current directory but can be changed with the `--config-file` and `--config-dir` options.
+By default it reads the `config.yml` file in the current directory but can be changed with the `--config-file` and `--config-dirs` options.
 
 This file is in YAML format with all options at root level.
 Keys are named after the command line options, with middle dashes `-` replaced with underscores `_` and a `s` appended for lists (option `--ibmcloud-url https://api...` will become `ibmcloud_url: https://api...` and `--keywords-file 1.json --keywords-file 2.json` will become :
diff --git a/docker/docker-entrypoint.sh b/docker/docker-entrypoint.sh
index 27e8479..8039453 100755
--- a/docker/docker-entrypoint.sh
+++ b/docker/docker-entrypoint.sh
@@ -72,7 +72,7 @@ case "${opt_bot}" in
     askbot|transbot)
         #exec python3 -m "nicobot.${opt_bot}" "$@"
         # TODO Allow to override config dirs with the docker command line
-        exec "${opt_bot}" "--config-dir" /etc/nicobot /var/nicobot "$@"
+        exec "${opt_bot}" "--config-dirs" /etc/nicobot /var/nicobot "$@"
         ;;
     *)
         echo "Unknown bot : '*{opt_bot}'" >2
diff --git a/nicobot/bot.py b/nicobot/bot.py
index 8892600..01990ac 100644
--- a/nicobot/bot.py
+++ b/nicobot/bot.py
@@ -90,7 +90,7 @@ class ArgsHelper:
 
         # Bootstrap options
         parser.add_argument("--config-file", "-c", "--config", dest="config_file", default=self.config_file, help="YAML configuration file.")
-        parser.add_argument("--config-dir", "-C", dest="config_dirs", nargs='+', default=self.config_dirs, help="Directories where to find configuration files by default.")
+        parser.add_argument("--config-dirs", "-C", dest="config_dirs", nargs='+', default=self.config_dirs, help="Directories where to find configuration files by default.")
         parser.add_argument('--verbosity', '-v', dest='verbosity', default=self.verbosity, help="Log level")
         # Chatter-generic arguments
         parser.add_argument("--backend", "-b", dest="backend", choices=['console','jabber','signal'], default=self.backend, help="Chat backend to use")
diff --git a/tests/test_options.py b/tests/test_options.py
index 06e617b..8012531 100644
--- a/tests/test_options.py
+++ b/tests/test_options.py
@@ -28,25 +28,25 @@ class TestOptions(unittest.TestCase):
         config = AskbotConfig()
         args = []
         config = parse_args_2pass( self.parser, args, config )
-        self.assertTrue( len(config.config_dirs) == 1 )
+        self.assertEqual( 1, len(config.config_dirs) )
         self.assertEqual( os.path.realpath(os.getcwd()), os.path.realpath(config.config_dirs[0]) )
 
     def test_config_path_custom(self):
 
         # Using AskbotConfig but it could be another one as long as this test is not askbot-specific
         config = AskbotConfig()
-        args = [ '--config-dir', '/tmp/nicobot' ]
+        args = [ '--config-dirs', '/tmp/nicobot' ]
         config = parse_args_2pass( self.parser, args, config )
-        self.assertTrue( len(config.config_dirs) == 1 )
+        self.assertEqual( 1, len(config.config_dirs) )
         self.assertEqual( os.path.realpath('/tmp/nicobot'), os.path.realpath(config.config_dirs[0]) )
 
     def test_config_path_default_and_custom(self):
 
         # Using AskbotConfig but it could be another one as long as this test is not askbot-specific
         config = AskbotConfig()
-        args = [ '--config-dir', '/etc/nicobot', '/tmp/nicobot' ]
+        args = [ '--config-dirs', '/etc/nicobot', '/tmp/nicobot' ]
         config = parse_args_2pass( self.parser, args, config )
-        self.assertTrue( len(config.config_dirs) == 2 )
+        self.assertEqual( 2, len(config.config_dirs) )
         self.assertEqual( os.path.realpath('/etc/nicobot'), os.path.realpath(config.config_dirs[0]) )
         self.assertEqual( os.path.realpath('/tmp/nicobot'), os.path.realpath(config.config_dirs[1]) )