diff --git a/actions/actions b/actions/actions
index e012b4b3c..7b7e5459b 100755
--- a/actions/actions
+++ b/actions/actions
@@ -9,6 +9,7 @@ import logging
 import os
 import sys
 import traceback
+import types
 import typing
 
 import plinth.log
@@ -166,10 +167,9 @@ def _assert_valid_type(arg_name, value, annotation):
 
         return
 
-    if not hasattr(annotation, '__origin__'):
-        raise TypeError('Unsupported annotation type')
-
-    if annotation.__origin__ == typing.Union:
+    # 'int | str' or 'typing.Union[int, str]'
+    if (isinstance(annotation, types.UnionType)
+            or getattr(annotation, '__origin__', None) == typing.Union):
         for arg in annotation.__args__:
             try:
                 _assert_valid_type(arg_name, value, arg)
@@ -179,7 +179,8 @@ def _assert_valid_type(arg_name, value, annotation):
 
         raise TypeError(f'Expected one of unioned types for {arg_name}')
 
-    if annotation.__origin__ == list:
+    # 'list[int]' or 'typing.List[int]'
+    if getattr(annotation, '__origin__', None) == list:
         if not isinstance(value, list):
             raise TypeError(f'Expected type list for {arg_name}')
 
@@ -189,7 +190,8 @@ def _assert_valid_type(arg_name, value, annotation):
 
         return
 
-    if annotation.__origin__ == dict:
+    # 'list[dict]' or 'typing.List[dict]'
+    if getattr(annotation, '__origin__', None) == dict:
         if not isinstance(value, dict):
             raise TypeError(f'Expected type dict for {arg_name}')
 
diff --git a/doc/dev/tutorial/customizing.rst b/doc/dev/tutorial/customizing.rst
index 46c2ad867..5b0aadd2c 100644
--- a/doc/dev/tutorial/customizing.rst
+++ b/doc/dev/tutorial/customizing.rst
@@ -160,7 +160,6 @@ for transmission daemon. We will do this by creating a file ``privileged.py``.
 
   import json
   import pathlib
-  from typing import Union
 
   from plinth import action_utils
   from plinth.actions import privileged
@@ -175,7 +174,7 @@ for transmission daemon. We will do this by creating a file ``privileged.py``.
 
 
   @privileged
-  def merge_configuration(configuration: dict[str, Union[str, bool]]) -> None:
+  def merge_configuration(configuration: dict[str, str | bool]) -> None:
       """Merge given JSON configuration with existing configuration."""
       current_configuration = _transmission_config.read_bytes()
       current_configuration = json.loads(current_configuration)
diff --git a/plinth/module_loader.py b/plinth/module_loader.py
index 4e4992851..cc2a561dd 100644
--- a/plinth/module_loader.py
+++ b/plinth/module_loader.py
@@ -8,7 +8,6 @@ import importlib
 import logging
 import pathlib
 import re
-from typing import Optional
 
 import django
 
@@ -142,8 +141,7 @@ def get_module_import_path(module_name: str) -> str:
     return import_path
 
 
-def _read_module_import_paths_from_file(
-        file_path: pathlib.Path) -> Optional[str]:
+def _read_module_import_paths_from_file(file_path: pathlib.Path) -> str | None:
     """Read a module's import path from a file."""
     with file_path.open() as file_handle:
         for line in file_handle:
diff --git a/plinth/modules/backups/privileged.py b/plinth/modules/backups/privileged.py
index d43cc4f6e..3ebc65178 100644
--- a/plinth/modules/backups/privileged.py
+++ b/plinth/modules/backups/privileged.py
@@ -7,7 +7,6 @@ import pathlib
 import re
 import subprocess
 import tarfile
-from typing import Optional, Union
 
 from plinth.actions import privileged
 from plinth.utils import Version
@@ -22,8 +21,8 @@ class AlreadyMountedError(Exception):
 
 
 @privileged
-def mount(mountpoint: str, remote_path: str, ssh_keyfile: Optional[str] = None,
-          password: Optional[str] = None,
+def mount(mountpoint: str, remote_path: str, ssh_keyfile: str | None = None,
+          password: str | None = None,
           user_known_hosts_file: str = '/dev/null'):
     """Mount a remote ssh path via sshfs."""
     try:
@@ -110,7 +109,7 @@ def setup(path: str):
 
 
 def _init_repository(path: str, encryption: str,
-                     encryption_passphrase: Optional[str] = None):
+                     encryption_passphrase: str | None = None):
     """Initialize a local or remote borg repository."""
     if encryption != 'none':
         if not encryption_passphrase:
@@ -121,14 +120,13 @@ def _init_repository(path: str, encryption: str,
 
 
 @privileged
-def init(path: str, encryption: str,
-         encryption_passphrase: Optional[str] = None):
+def init(path: str, encryption: str, encryption_passphrase: str | None = None):
     """Initialize the borg repository."""
     _init_repository(path, encryption, encryption_passphrase)
 
 
 @privileged
-def info(path: str, encryption_passphrase: Optional[str] = None) -> dict:
+def info(path: str, encryption_passphrase: str | None = None) -> dict:
     """Show repository information."""
     process = _run(['borg', 'info', '--json', path], encryption_passphrase,
                    stdout=subprocess.PIPE)
@@ -136,7 +134,7 @@ def info(path: str, encryption_passphrase: Optional[str] = None) -> dict:
 
 
 @privileged
-def list_repo(path: str, encryption_passphrase: Optional[str] = None) -> dict:
+def list_repo(path: str, encryption_passphrase: str | None = None) -> dict:
     """List repository contents."""
     process = _run(['borg', 'list', '--json', '--format="{comment}"', path],
                    encryption_passphrase, stdout=subprocess.PIPE)
@@ -150,8 +148,8 @@ def _get_borg_version():
 
 
 @privileged
-def create_archive(path: str, paths: list[str], comment: Optional[str] = None,
-                   encryption_passphrase: Optional[str] = None):
+def create_archive(path: str, paths: list[str], comment: str | None = None,
+                   encryption_passphrase: str | None = None):
     """Create archive."""
     existing_paths = filter(os.path.exists, paths)
     command = ['borg', 'create', '--json']
@@ -169,7 +167,7 @@ def create_archive(path: str, paths: list[str], comment: Optional[str] = None,
 
 
 @privileged
-def delete_archive(path: str, encryption_passphrase: Optional[str] = None):
+def delete_archive(path: str, encryption_passphrase: str | None = None):
     """Delete archive."""
     _run(['borg', 'delete', path], encryption_passphrase)
 
@@ -199,7 +197,7 @@ def _extract(archive_path, destination, encryption_passphrase, locations=None):
 
 
 @privileged
-def export_tar(path: str, encryption_passphrase: Optional[str] = None):
+def export_tar(path: str, encryption_passphrase: str | None = None):
     """Export archive contents as tar stream on stdout."""
     _run(['borg', 'export-tar', path, '-', '--tar-filter=gzip'],
          encryption_passphrase)
@@ -214,7 +212,7 @@ def _read_archive_file(archive, filepath, encryption_passphrase):
 
 @privileged
 def get_archive_apps(path: str,
-                     encryption_passphrase: Optional[str] = None) -> list[str]:
+                     encryption_passphrase: str | None = None) -> list[str]:
     """Get list of apps included in archive."""
     manifest_folder = os.path.relpath(MANIFESTS_FOLDER, '/')
     borg_call = [
@@ -286,7 +284,7 @@ def get_exported_archive_apps(path: str) -> list[str]:
 @privileged
 def restore_archive(archive_path: str, destination: str,
                     directories: list[str], files: list[str],
-                    encryption_passphrase: Optional[str] = None):
+                    encryption_passphrase: str | None = None):
     """Restore files from an archive."""
     locations_all = directories + files
     locations_all = [
@@ -319,8 +317,7 @@ def _assert_app_id(app_id):
 
 
 @privileged
-def dump_settings(app_id: str, settings: dict[str, Union[int, float, bool,
-                                                         str]]):
+def dump_settings(app_id: str, settings: dict[str, int | float | bool | str]):
     """Dump an app's settings to a JSON file."""
     _assert_app_id(app_id)
     BACKUPS_DATA_PATH.mkdir(exist_ok=True)
@@ -329,7 +326,7 @@ def dump_settings(app_id: str, settings: dict[str, Union[int, float, bool,
 
 
 @privileged
-def load_settings(app_id: str) -> dict[str, Union[int, float, bool, str]]:
+def load_settings(app_id: str) -> dict[str, int | float | bool | str]:
     """Load an app's settings from a JSON file."""
     _assert_app_id(app_id)
     settings_path = BACKUPS_DATA_PATH / f'{app_id}-settings.json'
@@ -339,7 +336,7 @@ def load_settings(app_id: str) -> dict[str, Union[int, float, bool, str]]:
         return {}
 
 
-def _get_env(encryption_passphrase: Optional[str] = None):
+def _get_env(encryption_passphrase: str | None = None):
     """Create encryption and ssh kwargs out of given arguments."""
     env = dict(os.environ, BORG_RELOCATED_REPO_ACCESS_IS_OK='yes',
                LANG='C.UTF-8')
diff --git a/plinth/modules/bepasty/privileged.py b/plinth/modules/bepasty/privileged.py
index d0e37bcb8..c9ddd7b63 100644
--- a/plinth/modules/bepasty/privileged.py
+++ b/plinth/modules/bepasty/privileged.py
@@ -11,7 +11,6 @@ import secrets
 import shutil
 import string
 import subprocess
-from typing import Optional
 
 import augeas
 
@@ -124,7 +123,7 @@ def get_configuration() -> dict[str, object]:
 
 
 @privileged
-def add_password(permissions: list[str], comment: Optional[str] = None):
+def add_password(permissions: list[str], comment: str | None = None):
     """Generate a password with given permissions."""
     conf = conf_file_read()
     permissions = _format_permissions(permissions)
diff --git a/plinth/modules/config/privileged.py b/plinth/modules/config/privileged.py
index ad5b7f58d..953b8d639 100644
--- a/plinth/modules/config/privileged.py
+++ b/plinth/modules/config/privileged.py
@@ -4,7 +4,6 @@
 import os
 import pathlib
 import subprocess
-from typing import Optional
 
 import augeas
 
@@ -29,7 +28,7 @@ def set_hostname(hostname: str):
 
 
 @privileged
-def set_domainname(domainname: Optional[str] = None):
+def set_domainname(domainname: str | None = None):
     """Set system domainname in /etc/hosts."""
     hostname = subprocess.check_output(['hostname']).decode().strip()
     hosts_path = pathlib.Path('/etc/hosts')
diff --git a/plinth/modules/ejabberd/__init__.py b/plinth/modules/ejabberd/__init__.py
index 0dbb12e54..3ee7771b0 100644
--- a/plinth/modules/ejabberd/__init__.py
+++ b/plinth/modules/ejabberd/__init__.py
@@ -3,7 +3,6 @@
 
 import json
 import logging
-from typing import Tuple
 
 from django.urls import reverse_lazy
 from django.utils.translation import gettext_lazy as _
@@ -226,7 +225,7 @@ def update_turn_configuration(config: TurnConfiguration, managed=True,
     privileged.configure_turn(json.loads(config.to_json()), managed)
 
 
-def get_turn_configuration() -> Tuple[TurnConfiguration, bool]:
+def get_turn_configuration() -> tuple[TurnConfiguration, bool]:
     """Get the latest STUN/TURN configuration."""
     tc, managed = privileged.get_turn_config()
     return TurnConfiguration(tc['domain'], tc['uris'],
diff --git a/plinth/modules/ejabberd/privileged.py b/plinth/modules/ejabberd/privileged.py
index e4dd971ce..7dd6e6498 100644
--- a/plinth/modules/ejabberd/privileged.py
+++ b/plinth/modules/ejabberd/privileged.py
@@ -8,7 +8,7 @@ import shutil
 import socket
 import subprocess
 from pathlib import Path
-from typing import Any, Optional, Tuple
+from typing import Any
 
 from ruamel.yaml import YAML, scalarstring
 
@@ -240,7 +240,7 @@ def set_domains(domains: list[str]):
 
 
 @privileged
-def mam(command: str) -> Optional[bool]:
+def mam(command: str) -> bool | None:
     """Enable, disable, or get status of Message Archive Management (MAM)."""
     if command not in ('enable', 'disable', 'status'):
         raise ValueError('Invalid command')
@@ -308,7 +308,7 @@ def _generate_uris(services: list[dict]) -> list[str]:
 
 
 @privileged
-def get_turn_config() -> Tuple[dict[str, Any], bool]:
+def get_turn_config() -> tuple[dict[str, Any], bool]:
     """Get the latest STUN/TURN configuration in JSON format."""
     with open(EJABBERD_CONFIG, 'r', encoding='utf-8') as file_handle:
         conf = yaml.load(file_handle)
diff --git a/plinth/modules/email/dns.py b/plinth/modules/email/dns.py
index fecd051b7..2540fc8f9 100644
--- a/plinth/modules/email/dns.py
+++ b/plinth/modules/email/dns.py
@@ -10,7 +10,6 @@ See: https://rspamd.com/doc/modules/dkim_signing.html
 """
 
 from dataclasses import dataclass
-from typing import Union
 
 
 @dataclass
@@ -19,12 +18,12 @@ class Entry:  # pylint: disable=too-many-instance-attributes
 
     type_: str
     value: str
-    domain: Union[str, None] = None
+    domain: str | None = None
     class_: str = 'IN'
     ttl: int = 60
     priority: int = 10
-    weight: Union[int, None] = None
-    port: Union[int, None] = None
+    weight: int | None = None
+    port: int | None = None
 
     def get_split_value(self):
         """If the record is TXT and value > 255, split it."""
diff --git a/plinth/modules/gitweb/privileged.py b/plinth/modules/gitweb/privileged.py
index bcd2dc5ce..2248ec776 100644
--- a/plinth/modules/gitweb/privileged.py
+++ b/plinth/modules/gitweb/privileged.py
@@ -9,7 +9,7 @@ import re
 import shutil
 import subprocess
 import time
-from typing import Any, Optional
+from typing import Any
 
 from plinth import action_utils
 from plinth.actions import privileged
@@ -347,7 +347,7 @@ def repo_info(name: str) -> dict[str, str]:
 
 
 @privileged
-def create_repo(url: Optional[str] = None, name: Optional[str] = None,
+def create_repo(url: str | None = None, name: str | None = None,
                 description: str = '', owner: str = '',
                 keep_ownership: bool = False, is_private: bool = False,
                 skip_prepare: bool = False, prepare_only: bool = False):
diff --git a/plinth/modules/i2p/privileged.py b/plinth/modules/i2p/privileged.py
index bd3c50395..9220bd698 100644
--- a/plinth/modules/i2p/privileged.py
+++ b/plinth/modules/i2p/privileged.py
@@ -1,8 +1,6 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 """Configure I2P."""
 
-from typing import Optional
-
 from plinth.actions import privileged
 from plinth.modules.i2p.helpers import RouterEditor, TunnelEditor
 
@@ -19,8 +17,8 @@ def set_tunnel_property(name: str, property_: str, value: str):
 
 
 @privileged
-def add_favorite(name: str, url: str, description: Optional[str],
-                 icon: Optional[str]):
+def add_favorite(name: str, url: str, description: str | None,
+                 icon: str | None):
     """Add a favorite to router.config."""
     editor = RouterEditor()
     editor.read_conf().add_favorite(name, url, description, icon).write_conf()
diff --git a/plinth/modules/ikiwiki/privileged.py b/plinth/modules/ikiwiki/privileged.py
index ffd711889..5f6c6357f 100644
--- a/plinth/modules/ikiwiki/privileged.py
+++ b/plinth/modules/ikiwiki/privileged.py
@@ -6,7 +6,6 @@ import pathlib
 import re
 import shutil
 import subprocess
-from typing import Tuple
 
 from plinth.actions import privileged
 
@@ -43,7 +42,7 @@ def _get_title(site):
 
 
 @privileged
-def get_sites() -> list[Tuple[str, str]]:
+def get_sites() -> list[tuple[str, str]]:
     """Get wikis and blogs."""
     sites = []
     if os.path.exists(SITE_PATH):
diff --git a/plinth/modules/matrixsynapse/privileged.py b/plinth/modules/matrixsynapse/privileged.py
index f5b48459d..8f29caaec 100644
--- a/plinth/modules/matrixsynapse/privileged.py
+++ b/plinth/modules/matrixsynapse/privileged.py
@@ -7,7 +7,6 @@ import json
 import os
 import pathlib
 import shutil
-from typing import Dict, List, Optional, Union
 
 import requests
 import yaml
@@ -102,7 +101,7 @@ def get_config():
 
 @privileged
 def set_config(public_registration: bool,
-               registration_verification: Optional[str] = None):
+               registration_verification: str | None = None):
     """Enable/disable public user registration."""
     if registration_verification == 'token':
         _create_registration_token()
@@ -243,7 +242,7 @@ def _get_access_token() -> str:
 
 
 @privileged
-def list_registration_tokens() -> List[Dict[str, Optional[Union[str, int]]]]:
+def list_registration_tokens() -> list[dict[str, str | int | None]]:
     """Return the current list of registration tokens."""
     if not action_utils.service_is_running('matrix-synapse'):
         return []
@@ -262,7 +261,7 @@ def _get_headers(access_token: str):
 
 
 def _list_registration_tokens(
-        access_token: str) -> List[Dict[str, Optional[Union[str, int]]]]:
+        access_token: str) -> list[dict[str, str | int | None]]:
     """Use Admin API to fetch the list of registration tokens.
 
     For details on registration tokens API, see:
diff --git a/plinth/modules/minetest/privileged.py b/plinth/modules/minetest/privileged.py
index ceae1812f..73452d7b9 100644
--- a/plinth/modules/minetest/privileged.py
+++ b/plinth/modules/minetest/privileged.py
@@ -1,8 +1,6 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 """Configure Minetest server."""
 
-from typing import Optional
-
 import augeas
 
 from plinth import action_utils
@@ -13,10 +11,9 @@ AUG_PATH = '/files' + CONFIG_FILE + '/.anon'
 
 
 @privileged
-def configure(max_players: Optional[int] = None,
-              enable_pvp: Optional[bool] = None,
-              creative_mode: Optional[bool] = None,
-              enable_damage: Optional[bool] = None):
+def configure(max_players: int | None = None, enable_pvp: bool | None = None,
+              creative_mode: bool | None = None,
+              enable_damage: bool | None = None):
     """Update configuration file and restart daemon if necessary."""
     aug = load_augeas()
     if max_players is not None:
diff --git a/plinth/modules/mumble/privileged.py b/plinth/modules/mumble/privileged.py
index 9ef198fab..9385a0f8c 100644
--- a/plinth/modules/mumble/privileged.py
+++ b/plinth/modules/mumble/privileged.py
@@ -5,7 +5,6 @@ Configure Mumble server.
 
 import pathlib
 import subprocess
-from typing import Optional
 
 import augeas
 
@@ -33,7 +32,7 @@ def set_super_user_password(password: str):
 
 
 @privileged
-def get_domain() -> Optional[str]:
+def get_domain() -> str | None:
     """Return domain name set in mumble or empty string."""
     domain_file = pathlib.Path('/var/lib/mumble-server/domain-freedombox')
     try:
@@ -43,7 +42,7 @@ def get_domain() -> Optional[str]:
 
 
 @privileged
-def set_domain(domain_name: Optional[str]):
+def set_domain(domain_name: str | None):
     """Write a file containing domain name."""
     if domain_name:
         domain_file = pathlib.Path('/var/lib/mumble-server/domain-freedombox')
@@ -69,7 +68,7 @@ def change_root_channel_name(root_channel_name: str):
 
 
 @privileged
-def get_root_channel_name() -> Optional[str]:
+def get_root_channel_name() -> str | None:
     """Return the currently configured Root channel name."""
     aug = _load_augeas()
     name = aug.get('.anon/registerName')
diff --git a/plinth/modules/privacy/privileged.py b/plinth/modules/privacy/privileged.py
index 04faff907..0a5782258 100644
--- a/plinth/modules/privacy/privileged.py
+++ b/plinth/modules/privacy/privileged.py
@@ -2,7 +2,6 @@
 """Configure Privacy App."""
 
 import pathlib
-from typing import Optional
 
 import augeas
 
@@ -30,7 +29,7 @@ def setup():
 
 
 @privileged
-def set_configuration(enable_popcon: Optional[bool] = None):
+def set_configuration(enable_popcon: bool | None = None):
     """Update popcon configuration."""
     aug = _load_augeas()
     if enable_popcon:
diff --git a/plinth/modules/shadowsocks/privileged.py b/plinth/modules/shadowsocks/privileged.py
index 4d3075654..1776cc6d9 100644
--- a/plinth/modules/shadowsocks/privileged.py
+++ b/plinth/modules/shadowsocks/privileged.py
@@ -7,7 +7,6 @@ import pathlib
 import random
 import string
 from shutil import move
-from typing import Union
 
 from plinth import action_utils
 from plinth.actions import privileged
@@ -64,7 +63,7 @@ def setup():
 
 
 @privileged
-def get_config() -> dict[str, Union[int, str]]:
+def get_config() -> dict[str, int | str]:
     """Read and print Shadowsocks configuration."""
     config = open(SHADOWSOCKS_CONFIG_SYMLINK, 'r', encoding='utf-8').read()
     return json.loads(config)
@@ -86,7 +85,7 @@ def _merge_config(config):
 
 
 @privileged
-def merge_config(config: dict[str, Union[int, str]]):
+def merge_config(config: dict[str, int | str]):
     """Configure Shadowsocks Client."""
     _merge_config(config)
 
diff --git a/plinth/modules/shadowsocksserver/privileged.py b/plinth/modules/shadowsocksserver/privileged.py
index 1e51bdccd..1ea5f16d2 100644
--- a/plinth/modules/shadowsocksserver/privileged.py
+++ b/plinth/modules/shadowsocksserver/privileged.py
@@ -6,7 +6,6 @@ import os
 import pathlib
 import random
 import string
-from typing import Union
 
 from plinth import action_utils
 from plinth.actions import privileged
@@ -47,7 +46,7 @@ def setup():
 
 
 @privileged
-def get_config() -> dict[str, Union[int, str]]:
+def get_config() -> dict[str, int | str]:
     """Read and print Shadowsocks Server configuration."""
     config = open(SHADOWSOCKS_CONFIG_SYMLINK, 'r', encoding='utf-8').read()
     return json.loads(config)
diff --git a/plinth/modules/tor/privileged.py b/plinth/modules/tor/privileged.py
index 4e6b37f10..c32a31dc5 100644
--- a/plinth/modules/tor/privileged.py
+++ b/plinth/modules/tor/privileged.py
@@ -10,7 +10,7 @@ import shutil
 import socket
 import subprocess
 import time
-from typing import Any, Optional, Union
+from typing import Any
 
 import augeas
 
@@ -143,11 +143,10 @@ def _remove_proxy():
 
 
 @privileged
-def configure(use_upstream_bridges: Optional[bool] = None,
-              upstream_bridges: Optional[str] = None,
-              relay: Optional[bool] = None,
-              bridge_relay: Optional[bool] = None,
-              hidden_service: Optional[bool] = None):
+def configure(use_upstream_bridges: bool | None = None,
+              upstream_bridges: str | None = None, relay: bool | None = None,
+              bridge_relay: bool | None = None,
+              hidden_service: bool | None = None):
     """Configure Tor."""
     aug = augeas_load()
 
@@ -193,7 +192,7 @@ def restart():
 
 
 @privileged
-def get_status() -> dict[str, Union[bool, str, dict[str, Any]]]:
+def get_status() -> dict[str, bool | str | dict[str, Any]]:
     """Return dict with Tor status."""
     aug = augeas_load()
     return {
@@ -323,8 +322,7 @@ def _disable():
     action_utils.service_disable(SERVICE_NAME)
 
 
-def _use_upstream_bridges(use_upstream_bridges: Optional[bool] = None,
-                          aug=None):
+def _use_upstream_bridges(use_upstream_bridges: bool | None = None, aug=None):
     """Enable use of upstream bridges."""
     if use_upstream_bridges is None:
         return
@@ -363,8 +361,7 @@ def _set_upstream_bridges(upstream_bridges=None, aug=None):
     aug.save()
 
 
-def _enable_relay(relay: Optional[bool], bridge: Optional[bool],
-                  aug: augeas.Augeas):
+def _enable_relay(relay: bool | None, bridge: bool | None, aug: augeas.Augeas):
     """Enable Tor bridge relay."""
     if relay is None and bridge is None:
         return
diff --git a/plinth/modules/torproxy/privileged.py b/plinth/modules/torproxy/privileged.py
index 57216af9d..46b12393d 100644
--- a/plinth/modules/torproxy/privileged.py
+++ b/plinth/modules/torproxy/privileged.py
@@ -5,7 +5,7 @@ import logging
 import os
 import shutil
 import subprocess
-from typing import Any, Optional, Union
+from typing import Any
 
 import augeas
 
@@ -66,9 +66,9 @@ def _first_time_setup():
 
 
 @privileged
-def configure(use_upstream_bridges: Optional[bool] = None,
-              upstream_bridges: Optional[str] = None,
-              apt_transport_tor: Optional[bool] = None):
+def configure(use_upstream_bridges: bool | None = None,
+              upstream_bridges: str | None = None,
+              apt_transport_tor: bool | None = None):
     """Configure Tor."""
     aug = augeas_load()
 
@@ -92,7 +92,7 @@ def restart():
 
 
 @privileged
-def get_status() -> dict[str, Union[bool, str, dict[str, Any]]]:
+def get_status() -> dict[str, bool | str | dict[str, Any]]:
     """Return dict with Tor Proxy status."""
     aug = augeas_load()
     return {
@@ -125,8 +125,7 @@ def _disable():
     action_utils.service_disable(SERVICE_NAME)
 
 
-def _use_upstream_bridges(use_upstream_bridges: Optional[bool] = None,
-                          aug=None):
+def _use_upstream_bridges(use_upstream_bridges: bool | None = None, aug=None):
     """Enable use of upstream bridges."""
     if use_upstream_bridges is None:
         return
diff --git a/plinth/modules/transmission/privileged.py b/plinth/modules/transmission/privileged.py
index 6c5992bdd..fbadd312a 100644
--- a/plinth/modules/transmission/privileged.py
+++ b/plinth/modules/transmission/privileged.py
@@ -5,7 +5,6 @@ Configuration helper for Transmission daemon.
 
 import json
 import pathlib
-from typing import Union
 
 from plinth import action_utils
 from plinth.actions import privileged
@@ -20,7 +19,7 @@ def get_configuration() -> dict[str, str]:
 
 
 @privileged
-def merge_configuration(configuration: dict[str, Union[str, bool]]):
+def merge_configuration(configuration: dict[str, str | bool]):
     """Merge given JSON configuration with existing configuration."""
     current_configuration_bytes = _transmission_config.read_bytes()
     current_configuration = json.loads(current_configuration_bytes)
diff --git a/plinth/modules/ttrss/privileged.py b/plinth/modules/ttrss/privileged.py
index 34778b596..a59aaf3ca 100644
--- a/plinth/modules/ttrss/privileged.py
+++ b/plinth/modules/ttrss/privileged.py
@@ -3,7 +3,6 @@
 
 import os
 import subprocess
-from typing import Optional
 
 import augeas
 
@@ -19,15 +18,16 @@ DB_BACKUP_FILE = '/var/lib/plinth/backups-data/ttrss-database.sql'
 @privileged
 def pre_setup():
     """Preseed debconf values before packages are installed."""
-    action_utils.debconf_set_selections(
-        ['tt-rss tt-rss/database-type string pgsql',
-         'tt-rss tt-rss/purge boolean true',
-         'tt-rss tt-rss/dbconfig-remove boolean true',
-         'tt-rss tt-rss/dbconfig-reinstall boolean true'])
+    action_utils.debconf_set_selections([
+        'tt-rss tt-rss/database-type string pgsql',
+        'tt-rss tt-rss/purge boolean true',
+        'tt-rss tt-rss/dbconfig-remove boolean true',
+        'tt-rss tt-rss/dbconfig-reinstall boolean true'
+    ])
 
 
 @privileged
-def get_domain() -> Optional[str]:
+def get_domain() -> str | None:
     """Get the domain set for Tiny Tiny RSS."""
     aug = load_augeas()
 
@@ -41,7 +41,7 @@ def get_domain() -> Optional[str]:
 
 
 @privileged
-def set_domain(domain_name: Optional[str]):
+def set_domain(domain_name: str | None):
     """Set the domain to be used by Tiny Tiny RSS."""
     if not domain_name:
         return
diff --git a/plinth/modules/upgrades/privileged.py b/plinth/modules/upgrades/privileged.py
index 1369e61b5..1b734d2b3 100644
--- a/plinth/modules/upgrades/privileged.py
+++ b/plinth/modules/upgrades/privileged.py
@@ -7,7 +7,6 @@ import pathlib
 import re
 import subprocess
 import time
-from typing import List, Tuple, Union
 
 from plinth.action_utils import (apt_hold, apt_hold_flag, apt_hold_freedombox,
                                  apt_unhold_freedombox, debconf_set_selections,
@@ -81,7 +80,7 @@ Pin: release a=bullseye-backports
 Pin-Priority: 500
 '''
 
-DIST_UPGRADE_OBSOLETE_PACKAGES: List[str] = []
+DIST_UPGRADE_OBSOLETE_PACKAGES: list[str] = []
 
 DIST_UPGRADE_PACKAGES_WITH_PROMPTS = [
     'bind9', 'firewalld', 'janus', 'minetest-server', 'minidlna',
@@ -90,7 +89,7 @@ DIST_UPGRADE_PACKAGES_WITH_PROMPTS = [
 
 DIST_UPGRADE_PRE_INSTALL_PACKAGES = ['base-files']
 
-DIST_UPGRADE_PRE_DEBCONF_SELECTIONS: List[str] = [
+DIST_UPGRADE_PRE_DEBCONF_SELECTIONS: list[str] = [
     # Tell grub-pc to continue without installing grub again.
     'grub-pc grub-pc/install_devices_empty boolean true'
 ]
@@ -317,7 +316,7 @@ def _is_sufficient_free_space() -> bool:
     return free_space >= DIST_UPGRADE_REQUIRED_FREE_SPACE
 
 
-def _check_dist_upgrade(test_upgrade=False) -> Tuple[bool, str]:
+def _check_dist_upgrade(test_upgrade=False) -> tuple[bool, str]:
     """Check if a distribution upgrade be performed.
 
     Check for new stable release, if updates are enabled, and if there is
@@ -589,7 +588,7 @@ def _start_dist_upgrade_service():
 
 
 @privileged
-def start_dist_upgrade(test: bool = False) -> dict[str, Union[str, bool]]:
+def start_dist_upgrade(test: bool = False) -> dict[str, str | bool]:
     """Start dist upgrade process.
 
     Check if a new stable release is available, and start dist-upgrade process
diff --git a/plinth/modules/users/privileged.py b/plinth/modules/users/privileged.py
index 7483474b1..a67284e84 100644
--- a/plinth/modules/users/privileged.py
+++ b/plinth/modules/users/privileged.py
@@ -6,7 +6,6 @@ import os
 import re
 import shutil
 import subprocess
-from typing import Optional
 
 import augeas
 
@@ -220,8 +219,8 @@ def _disconnect_samba_user(username):
 
 
 @privileged
-def create_user(username: str, password: str, auth_user: Optional[str] = None,
-                auth_password: Optional[str] = None):
+def create_user(username: str, password: str, auth_user: str | None = None,
+                auth_password: str | None = None):
     """Create an LDAP user, set password and flush cache."""
     _validate_user(auth_user, auth_password)
 
@@ -232,7 +231,7 @@ def create_user(username: str, password: str, auth_user: Optional[str] = None,
 
 
 @privileged
-def remove_user(username: str, password: Optional[str] = None):
+def remove_user(username: str, password: str | None = None):
     """Remove an LDAP user."""
     groups = _get_user_groups(username)
 
@@ -424,8 +423,8 @@ def _add_user_to_group(username, groupname):
 
 @privileged
 def add_user_to_group(username: str, groupname: str,
-                      auth_user: Optional[str] = None,
-                      auth_password: Optional[str] = None):
+                      auth_user: str | None = None,
+                      auth_password: str | None = None):
     """Add an LDAP user to an LDAP group."""
     if groupname == 'admin':
         _validate_user(auth_user, auth_password)
diff --git a/plinth/modules/zoph/privileged.py b/plinth/modules/zoph/privileged.py
index 65f342281..e5f3b79b9 100644
--- a/plinth/modules/zoph/privileged.py
+++ b/plinth/modules/zoph/privileged.py
@@ -5,7 +5,6 @@ import configparser
 import os
 import re
 import subprocess
-from typing import Optional
 
 from plinth import action_utils
 from plinth.actions import privileged
@@ -65,8 +64,8 @@ def _get_db_name():
 
 
 @privileged
-def set_configuration(enable_osm: Optional[bool] = None,
-                      admin_user: Optional[str] = None):
+def set_configuration(enable_osm: bool | None = None,
+                      admin_user: str | None = None):
     """Setup Zoph Apache configuration."""
     _zoph_configure('interface.user.remote', 'true')
 
@@ -90,7 +89,7 @@ def set_configuration(enable_osm: Optional[bool] = None,
 
 
 @privileged
-def is_configured() -> Optional[bool]:
+def is_configured() -> bool | None:
     """Return whether zoph app is configured."""
     try:
         process = subprocess.run(
diff --git a/plinth/operation.py b/plinth/operation.py
index 1985c8e08..ba6591e69 100644
--- a/plinth/operation.py
+++ b/plinth/operation.py
@@ -4,7 +4,7 @@
 import enum
 import logging
 import threading
-from typing import Callable, Optional
+from typing import Callable
 
 from . import app as app_module
 
@@ -22,10 +22,10 @@ class Operation:
         COMPLETED: str = 'completed'
 
     def __init__(self, app_id: str, name: str, target: Callable,
-                 args: Optional[list] = None, kwargs: Optional[dict] = None,
+                 args: list | None = None, kwargs: dict | None = None,
                  show_message: bool = True, show_notification: bool = False,
-                 thread_data: Optional[dict] = None,
-                 on_complete: Callable = None):
+                 thread_data: dict | None = None,
+                 on_complete: Callable | None = None):
         """Initialize to no operation."""
         self.app_id = app_id
         self.name = name
@@ -39,8 +39,8 @@ class Operation:
 
         self.state = Operation.State.WAITING
         self.return_value = None
-        self._message: Optional[str] = None
-        self.exception: Optional[Exception] = None
+        self._message: str | None = None
+        self.exception: Exception | None = None
 
         # Operation specific data
         self.thread_data: dict = thread_data or {}
@@ -94,8 +94,8 @@ class Operation:
         thread = threading.current_thread()
         return thread._operation  # type: ignore [attr-defined]
 
-    def on_update(self, message: Optional[str] = None,
-                  exception: Optional[Exception] = None):
+    def on_update(self, message: str | None = None,
+                  exception: Exception | None = None):
         """Call from within the thread to update the progress of operation."""
         if message:
             self._message = message
@@ -172,7 +172,7 @@ class OperationsManager:
     def __init__(self):
         """Initialize the object."""
         self._operations: list[Operation] = []
-        self._current_operation: Optional[Operation] = None
+        self._current_operation: Operation | None = None
 
         # Assume that operations manager will be called from various threads
         # including the callback called from the threads it creates. Ensure
diff --git a/plinth/package.py b/plinth/package.py
index dee7b9baf..c9afab8b2 100644
--- a/plinth/package.py
+++ b/plinth/package.py
@@ -5,7 +5,6 @@ import enum
 import logging
 import pathlib
 import time
-from typing import Optional, Union
 
 import apt.cache
 from django.utils.translation import gettext as _
@@ -42,11 +41,11 @@ class Package(PackageExpression):
             self,
             name,
             optional: bool = False,
-            version: Optional[str] = None,  # ">=1.0,<2.0"
-            distribution: Optional[str] = None,  # Debian, Ubuntu
-            suite: Optional[str] = None,  # stable, testing
-            codename: Optional[str] = None,  # bullseye-backports
-            architecture: Optional[str] = None):  # arm64
+            version: str | None = None,  # ">=1.0,<2.0"
+            distribution: str | None = None,  # Debian, Ubuntu
+            suite: str | None = None,  # stable, testing
+            codename: str | None = None,  # bullseye-backports
+            architecture: str | None = None):  # arm64
         self.name = name
         self.optional = optional
         self.version = version
@@ -108,10 +107,10 @@ class Packages(app_module.FollowerComponent):
         REMOVE = 'remove'  # Remove the packages before installing the app
 
     def __init__(self, component_id: str,
-                 packages: list[Union[str, PackageExpression]],
+                 packages: list[str | PackageExpression],
                  skip_recommends: bool = False,
-                 conflicts: Optional[list[str]] = None,
-                 conflicts_action: Optional[ConflictsAction] = None):
+                 conflicts: list[str] | None = None,
+                 conflicts_action: ConflictsAction | None = None):
         """Initialize a new packages component.
 
         'component_id' should be a unique ID across all components of an app
@@ -230,14 +229,14 @@ class Packages(app_module.FollowerComponent):
 
         return results
 
-    def find_conflicts(self) -> Optional[list[str]]:
+    def find_conflicts(self) -> list[str] | None:
         """Return list of conflicting packages installed on the system."""
         if not self.conflicts:
             return None
 
         return packages_installed(self.conflicts)
 
-    def has_unavailable_packages(self) -> Optional[bool]:
+    def has_unavailable_packages(self) -> bool | None:
         """Return whether any of the packages are not available.
 
         Returns True if one or more of the packages is not available in the
@@ -465,7 +464,7 @@ def filter_conffile_prompt_packages(packages):
     return privileged.filter_conffile_packages(list(packages))
 
 
-def packages_installed(candidates: Union[list, tuple]) -> list:
+def packages_installed(candidates: list | tuple) -> list:
     """Check which candidates are installed on the system.
 
     :param candidates: A list of package names.
diff --git a/plinth/privileged/packages.py b/plinth/privileged/packages.py
index a315f9144..9045d2fad 100644
--- a/plinth/privileged/packages.py
+++ b/plinth/privileged/packages.py
@@ -5,7 +5,7 @@ import logging
 import os
 import subprocess
 from collections import defaultdict
-from typing import Any, Optional
+from typing import Any
 
 import apt.cache
 import apt_inst
@@ -31,7 +31,7 @@ def update():
 
 @privileged
 def install(app_id: str, packages: list[str], skip_recommends: bool = False,
-            force_configuration: Optional[str] = None, reinstall: bool = False,
+            force_configuration: str | None = None, reinstall: bool = False,
             force_missing_configuration: bool = False):
     """Install packages using apt-get."""
     if force_configuration not in ('old', 'new', None):
diff --git a/plinth/tests/test_actions_actions.py b/plinth/tests/test_actions_actions.py
index 05c18b20c..088fa6fa4 100644
--- a/plinth/tests/test_actions_actions.py
+++ b/plinth/tests/test_actions_actions.py
@@ -147,9 +147,9 @@ def test_assert_valid_type(actions_module):
 
     # Invalid values for int, str, float and Optional
     values = [[1, bool], ['foo', int], [1, str], [1, float],
-              [1, typing.Optional[str]], [1.1, typing.Union[int, str]],
-              [1, list], [1, dict], [[1], list[str]],
-              [{
+              [1, typing.Optional[str]], [1, str | None],
+              [1.1, typing.Union[int, str]], [1.1, int | str], [1, list],
+              [1, dict], [[1], list[str]], [{
                   'a': 'b'
               }, dict[int, str]], [{
                   1: 2
@@ -165,8 +165,12 @@ def test_assert_valid_type(actions_module):
     assert_valid('arg', 1.1, float)
     assert_valid('arg', None, typing.Optional[int])
     assert_valid('arg', 1, typing.Optional[int])
+    assert_valid('arg', None, int | None)
+    assert_valid('arg', 1, int | None)
     assert_valid('arg', 1, typing.Union[int, str])
     assert_valid('arg', '1', typing.Union[int, str])
+    assert_valid('arg', 1, int | str)
+    assert_valid('arg', '1', int | str)
     assert_valid('arg', [], list[int])
     assert_valid('arg', ['foo'], list[str])
     assert_valid('arg', {}, dict[int, str])