diff --git a/.python-version b/.python-version
deleted file mode 100644
index d70c8f8d..00000000
--- a/.python-version
+++ /dev/null
@@ -1 +0,0 @@
-3.6
diff --git a/Makefile b/Makefile
index d45507b8..8511f143 100644
--- a/Makefile
+++ b/Makefile
@@ -136,11 +136,11 @@ lint: isort black flake8 pylint mypy
 
 .PHONY: isort
 isort:
-	isort --check --diff .
+	isort --check --diff src tests
 
 .PHONY: black
 black:
-	black --check --diff .
+	black --check --diff src tests
 
 .PHONY: flake8
 flake8:
@@ -157,8 +157,8 @@ mypy:
 
 .PHONY: format
 format:
-	isort .
-	black .
+	isort src tests
+	black src tests
 
 
 .PHONY: help
diff --git a/src/ch_tools/chadmin/chadmin_cli.py b/src/ch_tools/chadmin/chadmin_cli.py
index 2aff068e..27fb7edf 100755
--- a/src/ch_tools/chadmin/chadmin_cli.py
+++ b/src/ch_tools/chadmin/chadmin_cli.py
@@ -10,6 +10,7 @@
 
 import cloup
 
+from ch_tools import __version__
 from ch_tools.chadmin.cli.chs3_backup_group import chs3_backup_group
 from ch_tools.chadmin.cli.config_command import config_command
 from ch_tools.chadmin.cli.crash_log_group import crash_log_group
@@ -42,6 +43,7 @@
 from ch_tools.chadmin.cli.wait_started_command import wait_started_command
 from ch_tools.chadmin.cli.zookeeper_group import zookeeper_group
 from ch_tools.common.cli.context_settings import CONTEXT_SETTINGS
+from ch_tools.common.cli.locale_resolver import LocaleResolver
 from ch_tools.common.cli.parameters import TimeSpanParamType
 
 LOG_FILE = "/var/log/chadmin/chadmin.log"
@@ -71,6 +73,7 @@
 @cloup.option("--timeout", type=TimeSpanParamType(), help="Timeout for SQL queries.")
 @cloup.option("--port", type=int, help="Port to connect.")
 @cloup.option("-d", "--debug", is_flag=True, help="Enable debug output.")
+@cloup.version_option(__version__)
 @cloup.pass_context
 def cli(ctx, format_, settings, timeout, port, debug):
     """ClickHouse administration tool."""
@@ -147,4 +150,9 @@ def main():
     """
     Program entry point.
     """
+    LocaleResolver.resolve()
     cli.main()
+
+
+if __name__ == "__main__":
+    main()
diff --git a/src/ch_tools/common/cli/locale_resolver.py b/src/ch_tools/common/cli/locale_resolver.py
new file mode 100644
index 00000000..f63b2b4d
--- /dev/null
+++ b/src/ch_tools/common/cli/locale_resolver.py
@@ -0,0 +1,81 @@
+import locale
+import os
+import subprocess
+from typing import List, Tuple
+
+__all__ = [
+    "LocaleResolver",
+]
+
+
+class LocaleResolver:
+    """
+    Sets the locale for Click. Otherwise, it may fail with an error like
+
+    ```
+    RuntimeError: Click discovered that you exported a UTF-8 locale
+    but the locale system could not pick up from it because it does not exist.
+    The exported locale is 'en_US.UTF-8' but it is not supported.
+    ```
+    """
+
+    @staticmethod
+    def resolve():
+        lang, _ = locale.getlocale()
+        locales, has_c, has_en_us = LocaleResolver._get_utf8_locales()
+
+        langs = map(lambda loc: str.lower(loc[0]), locales)
+        if lang is None or lang.lower() not in langs:
+            if has_c:
+                lang = "C"
+            elif has_en_us:
+                lang = "en_US"
+            else:
+                raise RuntimeError(
+                    f'Locale "{lang}" is not supported. '
+                    'We tried to use "C" and "en_US" but they\'re absent on your machine.',
+                )
+
+        for locale_ in locales:
+            if lang != locale_[0]:
+                continue
+
+            os.environ["LC_ALL"] = f"{lang}.{locale_[1]}"
+            os.environ["LANG"] = f"{lang}.{locale_[1]}"
+
+    @staticmethod
+    def _get_utf8_locales() -> Tuple[List[Tuple[str, str]], bool, bool]:
+        try:
+            with subprocess.Popen(
+                ["locale", "-a"],
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+                encoding="ascii",
+                errors="replace",
+            ) as proc:
+                stdout, _ = proc.communicate()
+        except OSError:
+            stdout = ""
+
+        langs = []
+        encodings = []
+
+        has_c = False
+        has_en_us = False
+
+        for line in stdout.splitlines():
+            locale_ = line.strip()
+            if not locale_.lower().endswith(("utf-8", "utf8")):
+                continue
+
+            lang, encoding = locale_.split(".")
+
+            langs.append(lang)
+            encodings.append(encoding)
+
+            has_c |= lang.lower() == "c"
+            has_en_us |= lang.lower() == "en_us"
+
+        res = list(zip(langs, encodings))
+
+        return res, has_c, has_en_us
diff --git a/src/ch_tools/monrun_checks/main.py b/src/ch_tools/monrun_checks/main.py
index 19d78a88..10ce1c4d 100644
--- a/src/ch_tools/monrun_checks/main.py
+++ b/src/ch_tools/monrun_checks/main.py
@@ -5,13 +5,18 @@
 import sys
 import warnings
 from functools import wraps
+from typing import Optional
 
 warnings.filterwarnings(action="ignore", message="Python 3.6 is no longer supported")
 
 # pylint: disable=wrong-import-position
 
 import click
+import cloup
 
+from ch_tools import __version__
+from ch_tools.common.cli.context_settings import CONTEXT_SETTINGS
+from ch_tools.common.cli.locale_resolver import LocaleResolver
 from ch_tools.common.result import Status
 from ch_tools.monrun_checks.ch_backup import backup_command
 from ch_tools.monrun_checks.ch_core_dumps import core_dumps_command
@@ -33,13 +38,30 @@
 LOG_FILE = "/var/log/clickhouse-monitoring/clickhouse-monitoring.log"
 DEFAULT_USER = "monitor"
 
+# pylint: disable=too-many-ancestors
+
+
+class MonrunChecks(cloup.Group):
+    def add_command(
+        self,
+        cmd: click.Command,
+        name: Optional[str] = None,
+        section: Optional[cloup.Section] = None,
+        fallback_to_default_section: bool = True,
+    ) -> None:
+        if cmd.callback is None:
+            super().add_command(
+                cmd,
+                name=name,
+                section=section,
+                fallback_to_default_section=fallback_to_default_section,
+            )
+            return
 
-class MonrunChecks(click.Group):
-    def add_command(self, cmd, name=None):
         cmd_callback = cmd.callback
 
         @wraps(cmd_callback)
-        @click.pass_context
+        @cloup.pass_context
         def callback_wrapper(ctx, *args, **kwargs):
             os.makedirs(os.path.dirname(LOG_FILE), exist_ok=True)
             logging.basicConfig(
@@ -75,23 +97,26 @@ def callback_wrapper(ctx, *args, **kwargs):
             status.report()
 
         cmd.callback = callback_wrapper
-        super().add_command(cmd, name=name)
+        super().add_command(
+            cmd,
+            name=name,
+            section=section,
+            fallback_to_default_section=fallback_to_default_section,
+        )
 
 
-@click.group(
+@cloup.group(
     cls=MonrunChecks,
-    context_settings={
-        "help_option_names": ["-h", "--help"],
-        "terminal_width": 120,
-    },
+    context_settings=CONTEXT_SETTINGS,
 )
-@click.option(
+@cloup.option(
     "--no-user-check",
     "no_user_check",
     is_flag=True,
     default=False,
     help="Do not check current user.",
 )
+@cloup.version_option(__version__)
 def cli(no_user_check):
     if not no_user_check:
         check_current_user()
@@ -124,8 +149,8 @@ def main():
     """
     Program entry point.
     """
-    # pylint: disable=no-value-for-parameter
-    cli()
+    LocaleResolver.resolve()
+    cli.main()
 
 
 def check_current_user():
@@ -148,3 +173,7 @@ def check_current_user():
             except Exception as exc:
                 print(repr(exc), file=sys.stderr)
                 sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/src/ch_tools/monrun_checks_keeper/main.py b/src/ch_tools/monrun_checks_keeper/main.py
index 32bfbc10..81a1a7a3 100644
--- a/src/ch_tools/monrun_checks_keeper/main.py
+++ b/src/ch_tools/monrun_checks_keeper/main.py
@@ -1,10 +1,14 @@
 import logging
 import os
 from functools import wraps
+from typing import Optional
 
 import click
-from click import group, option, pass_context
+import cloup
 
+from ch_tools import __version__
+from ch_tools.common.cli.context_settings import CONTEXT_SETTINGS
+from ch_tools.common.cli.locale_resolver import LocaleResolver
 from ch_tools.common.result import Status
 from ch_tools.monrun_checks_keeper.keeper_commands import (
     alive_command,
@@ -21,13 +25,30 @@
 
 LOG_FILE = "/var/log/keeper-monitoring/keeper-monitoring.log"
 
+# pylint: disable=too-many-ancestors
+
+
+class KeeperChecks(cloup.Group):
+    def add_command(
+        self,
+        cmd: click.Command,
+        name: Optional[str] = None,
+        section: Optional[cloup.Section] = None,
+        fallback_to_default_section: bool = True,
+    ) -> None:
+        if cmd.callback is None:
+            super().add_command(
+                cmd,
+                name=name,
+                section=section,
+                fallback_to_default_section=fallback_to_default_section,
+            )
+            return
 
-class KeeperChecks(click.Group):
-    def add_command(self, cmd, name=None):
         cmd_callback = cmd.callback
 
         @wraps(cmd_callback)
-        @click.pass_context
+        @cloup.pass_context
         def wrapper(ctx, *a, **kw):
             os.makedirs(os.path.dirname(LOG_FILE), exist_ok=True)
             logging.basicConfig(
@@ -58,12 +79,22 @@ def wrapper(ctx, *a, **kw):
             status.report()
 
         cmd.callback = wrapper
-        super().add_command(cmd, name=name)
+        super().add_command(
+            cmd,
+            name=name,
+            section=section,
+            fallback_to_default_section=fallback_to_default_section,
+        )
 
 
-@group(cls=KeeperChecks, context_settings={"help_option_names": ["-h", "--help"]})
-@option("-r", "--retries", "retries", type=int, default=3, help="Number of retries")
-@option(
+@cloup.group(
+    cls=KeeperChecks,
+    context_settings=CONTEXT_SETTINGS,
+)
+@cloup.option(
+    "-r", "--retries", "retries", type=int, default=3, help="Number of retries"
+)
+@cloup.option(
     "-t",
     "--timeout",
     "timeout",
@@ -71,7 +102,7 @@ def wrapper(ctx, *a, **kw):
     default=0.5,
     help="Connection timeout (in seconds)",
 )
-@option(
+@cloup.option(
     "-n",
     "--no-verify-ssl-certs",
     "no_verify_ssl_certs",
@@ -79,7 +110,8 @@ def wrapper(ctx, *a, **kw):
     default=False,
     help="Allow unverified SSL certificates, e.g. self-signed ones",
 )
-@pass_context
+@cloup.version_option(__version__)
+@cloup.pass_context
 def cli(ctx, retries, timeout, no_verify_ssl_certs):
     ctx.obj = dict(
         retries=retries, timeout=timeout, no_verify_ssl_certs=no_verify_ssl_certs
@@ -108,5 +140,9 @@ def main():
     """
     Program entry point.
     """
-    # pylint: disable=no-value-for-parameter
-    cli()
+    LocaleResolver.resolve()
+    cli.main()
+
+
+if __name__ == "__main__":
+    main()