diff --git a/lib/hidapi/hidapi.py b/lib/hidapi/hidapi.py
index 18464f9cd6..a9cbf82f04 100644
--- a/lib/hidapi/hidapi.py
+++ b/lib/hidapi/hidapi.py
@@ -33,6 +33,11 @@
 from threading import Thread
 from time import sleep
 
+import gi
+
+gi.require_version('Gdk', '3.0')
+from gi.repository import GLib  # NOQA: E402
+
 logger = logging.getLogger(__name__)
 
 native_implementation = 'hidapi'
@@ -257,7 +262,7 @@ def _match(action, device, filterfn):
             device['hidpp_long'] = True
     except HIDError as e:  # noqa: F841
         if logger.isEnabledFor(logging.INFO):
-            logger.info(f"Error opening device {device['path']} ({bus_id}/{vid:04X}/{pid:04X}) for hidpp check: {e}")
+            logger.info(f"Error opening device {device['path']} ({bus_id}/{vid:04X}/{pid:04X}) for hidpp check: {e}")  # noqa
     finally:
         if device_handle:
             close(device_handle)
@@ -279,8 +284,8 @@ def _match(action, device, filterfn):
         d_info = DeviceInfo(
             path=device['path'].decode(),
             bus_id=bus_id,
-            vendor_id=f'{vid:04X}',
-            product_id=f'{pid:04X}',
+            vendor_id=f'{vid:04X}',  # noqa
+            product_id=f'{pid:04X}',  # noqa
             interface=None,
             driver=None,
             manufacturer=device['manufacturer_string'],
@@ -297,8 +302,8 @@ def _match(action, device, filterfn):
         d_info = DeviceInfo(
             path=device['path'].decode(),
             bus_id=None,
-            vendor_id=f'{vid:04X}',
-            product_id=f'{pid:04X}',
+            vendor_id=f'{vid:04X}',  # noqa
+            product_id=f'{pid:04X}',  # noqa
             interface=None,
             driver=None,
             manufacturer=None,
@@ -323,7 +328,6 @@ def find_paired_node_wpid(receiver_path, index):
 
 
 def monitor_glib(callback, filterfn):
-    from gi.repository import GLib
 
     def device_callback(action, device):
         # print(f"device_callback({action}): {device}")
diff --git a/lib/hidapi/hidconsole.py b/lib/hidapi/hidconsole.py
index bc7bf4c043..a37dd1fa41 100644
--- a/lib/hidapi/hidconsole.py
+++ b/lib/hidapi/hidconsole.py
@@ -16,13 +16,16 @@
 ## with this program; if not, write to the Free Software Foundation, Inc.,
 ## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+import argparse
 import os
+import os.path
+import readline
 import sys
 import time
 
 from binascii import hexlify, unhexlify
 from select import select as _select
-from threading import Lock
+from threading import Lock, Thread
 
 import hidapi as _hid
 
@@ -176,7 +179,6 @@ def matchfn(bid, vid, pid, _a, _b):
 
 
 def _parse_arguments():
-    import argparse
     arg_parser = argparse.ArgumentParser()
     arg_parser.add_argument('--history', help='history file (default ~/.hidconsole-history)')
     arg_parser.add_argument('--hidpp', action='store_true', help='ensure input data is a valid HID++ request')
@@ -196,9 +198,7 @@ def main():
     if interactive:
         print('.. Press ^C/^D to exit, or type hex bytes to write to the device.')
 
-        import readline
         if args.history is None:
-            import os.path
             args.history = os.path.join(os.path.expanduser('~'), '.hidconsole-history')
         try:
             readline.read_history_file(args.history)
@@ -207,7 +207,6 @@ def main():
             pass
 
     try:
-        from threading import Thread
         t = Thread(target=_continuous_read, args=(handle, ))
         t.daemon = True
         t.start()
diff --git a/lib/hidapi/udev.py b/lib/hidapi/udev.py
index aaa11698bc..2329767877 100644
--- a/lib/hidapi/udev.py
+++ b/lib/hidapi/udev.py
@@ -35,12 +35,18 @@
 from time import sleep
 from time import time as _timestamp
 
+import gi
+
+from hid_parser import ReportDescriptor as _ReportDescriptor
 from pyudev import Context as _Context
 from pyudev import Device as _Device
 from pyudev import DeviceNotFoundError
 from pyudev import Devices as _Devices
 from pyudev import Monitor as _Monitor
 
+gi.require_version('Gdk', '3.0')
+from gi.repository import GLib  # NOQA: E402
+
 logger = logging.getLogger(__name__)
 
 native_implementation = 'udev'
@@ -105,9 +111,6 @@ def _match(action, device, filterfn):
         return  # these are devices connected through a receiver so don't pick them up here
 
     try:  # if report descriptor does not indicate HID++ capabilities then this device is not of interest to Solaar
-        from hid_parser import ReportDescriptor as _ReportDescriptor
-
-        # from hid_parser import Usage as _Usage
         hidpp_short = hidpp_long = False
         devfile = '/sys' + hid_device.get('DEVPATH') + '/report_descriptor'
         with fileopen(devfile, 'rb') as fd:
@@ -236,8 +239,6 @@ def find_paired_node_wpid(receiver_path, index):
 
 
 def monitor_glib(callback, filterfn):
-    from gi.repository import GLib
-
     c = _Context()
 
     # already existing devices
diff --git a/lib/logitech_receiver/diversion.py b/lib/logitech_receiver/diversion.py
index adbb6050ef..3da2510f90 100644
--- a/lib/logitech_receiver/diversion.py
+++ b/lib/logitech_receiver/diversion.py
@@ -18,14 +18,20 @@
 
 import ctypes as _ctypes
 import logging
+import math
+import numbers
 import os as _os
 import os.path as _path
 import platform as _platform
+import socket
+import subprocess
 import sys as _sys
 import time as _time
 
-from math import sqrt as _sqrt
-from struct import unpack as _unpack
+import dbus
+import gi
+import keysyms.keysymdef as _keysymdef
+import psutil
 
 # There is no evdev on macOS or Windows. Diversion will not work without
 # it but other Solaar functionality is available.
@@ -34,9 +40,8 @@
 else:
     import evdev
 
-import dbus
-import keysyms.keysymdef as _keysymdef
-import psutil
+from math import sqrt as _sqrt
+from struct import unpack as _unpack
 
 from yaml import add_representer as _yaml_add_representer
 from yaml import dump_all as _yaml_dump_all
@@ -46,8 +51,6 @@
 from .hidpp20 import FEATURE as _F
 from .special_keys import CONTROL as _CONTROL
 
-import gi  # isort:skip
-
 gi.require_version('Gdk', '3.0')  # isort:skip
 from gi.repository import Gdk, GLib  # NOQA: E402 # isort:skip
 
@@ -1082,7 +1085,6 @@ def __str__(self):
     def evaluate(self, feature, notification, device, status, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug('evaluate condition: %s', self)
-        import socket
         hostname = socket.getfqdn()
         return hostname.startswith(self.host)
 
@@ -1206,7 +1208,6 @@ def data(self):
 class MouseScroll(Action):
 
     def __init__(self, amounts, warn=True):
-        import numbers
         if len(amounts) == 1 and isinstance(amounts[0], list):
             amounts = amounts[0]
         if not (len(amounts) == 2 and all([isinstance(a, numbers.Number) for a in amounts])):
@@ -1219,8 +1220,6 @@ def __str__(self):
         return 'MouseScroll: ' + ' '.join([str(a) for a in self.amounts])
 
     def evaluate(self, feature, notification, device, status, last_result):
-        import math
-        import numbers
         amounts = self.amounts
         if isinstance(last_result, numbers.Number):
             amounts = [math.floor(last_result * a) for a in self.amounts]
@@ -1328,7 +1327,6 @@ def __str__(self):
         return 'Execute: ' + ' '.join([a for a in self.args])
 
     def evaluate(self, feature, notification, device, status, last_result):
-        import subprocess
         if logger.isEnabledFor(logging.INFO):
             logger.info('Execute action: %s', self.args)
         subprocess.Popen(self.args)
diff --git a/lib/logitech_receiver/hidpp20.py b/lib/logitech_receiver/hidpp20.py
index 4032d1c96c..42d0f545d9 100644
--- a/lib/logitech_receiver/hidpp20.py
+++ b/lib/logitech_receiver/hidpp20.py
@@ -19,6 +19,7 @@
 # Logitech Unifying Receiver API.
 
 import logging
+import socket
 import threading as _threading
 
 from struct import pack as _pack
@@ -2003,7 +2004,6 @@ def get_host_names(device):
                         remaining = 0
                 host_names[host] = (bool(status), name)
         # update the current host's name if it doesn't match the system name
-        import socket
         hostname = socket.gethostname().partition('.')[0]
         if host_names[currentHost][1] != hostname:
             set_host_name(device, hostname, host_names[currentHost][1])
diff --git a/lib/solaar/configuration.py b/lib/solaar/configuration.py
index b011b50017..7066a0b984 100644
--- a/lib/solaar/configuration.py
+++ b/lib/solaar/configuration.py
@@ -26,6 +26,7 @@
 
 import yaml as _yaml
 
+from gi.repository import GLib
 from logitech_receiver.common import NamedInt as _NamedInt
 from solaar import __version__
 
@@ -142,7 +143,6 @@ def save(defer=False):
     else:
         with save_lock:
             if not save_timer:
-                from gi.repository import GLib
                 save_timer = _Timer(5.0, lambda: GLib.idle_add(do_save))
                 save_timer.start()
 
diff --git a/lib/solaar/gtk.py b/lib/solaar/gtk.py
index b4e3ed85f2..0bb54660f8 100755
--- a/lib/solaar/gtk.py
+++ b/lib/solaar/gtk.py
@@ -18,6 +18,8 @@
 ## with this program; if not, write to the Free Software Foundation, Inc.,
 ## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+import argparse
+import faulthandler
 import importlib
 import logging
 import os.path
@@ -26,8 +28,15 @@
 import sys
 import tempfile
 
+from traceback import format_exc
+
 import solaar.cli as _cli
+import solaar.configuration as _configuration
 import solaar.i18n as _i18n
+import solaar.listener as _listener
+import solaar.ui as _ui
+import solaar.ui.common as _common
+import solaar.upower as _upower
 
 from solaar import NAME, __version__
 
@@ -52,7 +61,6 @@ def _require(module, os_package, gi=None, gi_package=None, gi_version=None):
 
 
 def _parse_arguments():
-    import argparse
     arg_parser = argparse.ArgumentParser(
         prog=NAME.lower(), epilog='For more information see https://pwr-solaar.github.io/Solaar'
     )
@@ -122,7 +130,6 @@ def _parse_arguments():
 
 # On first SIGINT, dump threads to stderr; on second, exit
 def _handlesig(signl, stack):
-    import faulthandler
     signal.signal(signal.SIGINT, signal.SIG_DFL)
     signal.signal(signal.SIGTERM, signal.SIG_DFL)
 
@@ -161,25 +168,18 @@ def main():
         logger.warning('Solaar udev file not found in expected location')
         logger.warning('See https://pwr-solaar.github.io/Solaar/installation for more information')
     try:
-        import solaar.listener as listener
-        import solaar.ui as ui
-        import solaar.ui.common as common
-
-        listener.setup_scanner(ui.status_changed, common.error_dialog)
+        _listener.setup_scanner(_ui.status_changed, _common.error_dialog)
 
-        import solaar.upower as _upower
         if args.restart_on_wake_up:
-            _upower.watch(listener.start_all, listener.stop_all)
+            _upower.watch(_listener.start_all, _listener.stop_all)
         else:
-            _upower.watch(lambda: listener.ping_all(True))
+            _upower.watch(lambda: _listener.ping_all(True))
 
-        import solaar.configuration as _configuration
         _configuration.defer_saves = True  # allow configuration saves to be deferred
 
         # main UI event loop
-        ui.run_loop(listener.start_all, listener.stop_all, args.window != 'only', args.window != 'hide')
+        _ui.run_loop(_listener.start_all, _listener.stop_all, args.window != 'only', args.window != 'hide')
     except Exception:
-        from traceback import format_exc
         sys.exit('%s: error: %s' % (NAME.lower(), format_exc()))
 
     temp.close()
diff --git a/lib/solaar/i18n.py b/lib/solaar/i18n.py
index 7eddb7ef31..162ff8ed22 100644
--- a/lib/solaar/i18n.py
+++ b/lib/solaar/i18n.py
@@ -18,6 +18,10 @@
 
 import gettext as _gettext
 import locale
+import os.path as _path
+import sys as _sys
+
+from glob import glob as _glob
 
 from solaar import NAME as _NAME
 
@@ -27,13 +31,8 @@
 
 
 def _find_locale_path(lc_domain):
-    import os.path as _path
-    import sys as _sys
     prefix_share = _path.normpath(_path.join(_path.realpath(_sys.path[0]), '..'))
     src_share = _path.normpath(_path.join(_path.realpath(_sys.path[0]), '..', 'share'))
-    del _sys
-
-    from glob import glob as _glob
 
     for location in prefix_share, src_share:
         mo_files = _glob(_path.join(location, 'locale', '*', 'LC_MESSAGES', lc_domain + '.mo'))
diff --git a/lib/solaar/listener.py b/lib/solaar/listener.py
index 3ddba6d5be..94b39605f9 100644
--- a/lib/solaar/listener.py
+++ b/lib/solaar/listener.py
@@ -18,6 +18,7 @@
 
 import errno as _errno
 import logging
+import subprocess
 import time
 
 from collections import namedtuple
@@ -390,7 +391,6 @@ def _process_add(device_info, retry):
     except OSError as e:
         if e.errno == _errno.EACCES:
             try:
-                import subprocess
                 output = subprocess.check_output(['/usr/bin/getfacl', '-p', device_info.path], text=True)
                 if logger.isEnabledFor(logging.WARNING):
                     logger.warning('Missing permissions on %s\n%s.', device_info.path, output)
diff --git a/lib/solaar/ui/__init__.py b/lib/solaar/ui/__init__.py
index 449f78f6b7..b8673ffb14 100644
--- a/lib/solaar/ui/__init__.py
+++ b/lib/solaar/ui/__init__.py
@@ -21,7 +21,6 @@
 import gi
 import yaml as _yaml
 
-from gi.repository import Gio, GLib, Gtk
 from logitech_receiver.status import ALERT
 from solaar.i18n import _
 from solaar.tasks import TaskRunner as _TaskRunner
@@ -31,6 +30,8 @@
 from . import diversion_rules, notify, tray, window
 
 gi.require_version('Gtk', '3.0')
+from gi.repository import Gio, GLib, Gtk  # NOQA: E402
+
 logger = logging.getLogger(__name__)
 
 #
diff --git a/lib/solaar/ui/common.py b/lib/solaar/ui/common.py
index 4b7f219e68..22440f885a 100644
--- a/lib/solaar/ui/common.py
+++ b/lib/solaar/ui/common.py
@@ -18,9 +18,13 @@
 
 import logging
 
-from gi.repository import GLib, Gtk
+import gi
+
 from solaar.i18n import _
 
+gi.require_version('Gtk', '3.0')
+from gi.repository import GLib, Gtk  # NOQA: E402
+
 logger = logging.getLogger(__name__)
 
 
diff --git a/lib/solaar/ui/config_panel.py b/lib/solaar/ui/config_panel.py
index 49fa4e81fb..d97f2e5a93 100644
--- a/lib/solaar/ui/config_panel.py
+++ b/lib/solaar/ui/config_panel.py
@@ -21,7 +21,8 @@
 
 from threading import Timer as _Timer
 
-from gi.repository import Gdk, GLib, Gtk
+import gi
+
 from logitech_receiver.hidpp20 import LEDEffectSetting as _LEDEffectSetting
 from logitech_receiver.settings import KIND as _SETTING_KIND
 from logitech_receiver.settings import SENSITIVITY_IGNORE as _SENSITIVITY_IGNORE
@@ -29,6 +30,9 @@
 
 from .common import ui_async as _ui_async
 
+gi.require_version('Gtk', '3.0')
+from gi.repository import Gdk, GLib, Gtk  # NOQA: E402
+
 logger = logging.getLogger(__name__)
 
 #
diff --git a/lib/solaar/ui/tray.py b/lib/solaar/ui/tray.py
index c615943461..01f32049aa 100644
--- a/lib/solaar/ui/tray.py
+++ b/lib/solaar/ui/tray.py
@@ -21,6 +21,7 @@
 
 from time import time as _timestamp
 
+import gi
 import solaar.gtk as gtk
 
 from gi.repository import GLib, Gtk
@@ -144,7 +145,6 @@ def _scroll(tray_icon, event, direction=None):
 
 
 try:
-    import gi
     try:
         gi.require_version('AyatanaAppIndicator3', '0.1')
         from gi.repository import AyatanaAppIndicator3 as AppIndicator3
diff --git a/setup.py b/setup.py
index 2189e7638e..393d281355 100755
--- a/setup.py
+++ b/setup.py
@@ -2,6 +2,7 @@
 import subprocess
 
 from glob import glob as _glob
+from os.path import dirname as _dirname
 
 try:
     from setuptools import setup
@@ -29,7 +30,6 @@
 
 
 def _data_files():
-    from os.path import dirname as _dirname
 
     yield 'share/icons/hicolor/scalable/apps', _glob('share/solaar/icons/solaar*.svg')
     yield 'share/icons/hicolor/32x32/apps', _glob('share/solaar/icons/solaar-light_*.png')
@@ -41,8 +41,6 @@ def _data_files():
     yield 'lib/udev/rules.d', ['rules.d/42-logitech-unify-permissions.rules']
     yield 'share/metainfo', ['share/solaar/io.github.pwr_solaar.solaar.metainfo.xml']
 
-    del _dirname
-
 
 setup(
     name=NAME.lower(),