diff --git a/lib/logitech_receiver/diversion.py b/lib/logitech_receiver/diversion.py
index 411ae7ed..e5a05497 100644
--- a/lib/logitech_receiver/diversion.py
+++ b/lib/logitech_receiver/diversion.py
@@ -14,6 +14,8 @@
 ## with this program; if not, write to the Free Software Foundation, Inc.,
 ## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+from __future__ import annotations
+
 import ctypes
 import logging
 import math
@@ -25,6 +27,7 @@ import struct
 import subprocess
 import sys
 import time
+import typing
 
 from typing import Any
 from typing import Dict
@@ -50,6 +53,9 @@ from .special_keys import CONTROL
 gi.require_version("Gdk", "3.0")  # isort:skip
 from gi.repository import Gdk, GLib  # NOQA: E402 # isort:skip
 
+if typing.TYPE_CHECKING:
+    from .base import HIDPPNotification
+
 logger = logging.getLogger(__name__)
 
 #
@@ -518,7 +524,7 @@ class RuleComponent:
         return Condition()
 
 
-def _evaluate(components, feature, notification, device, result) -> Any:
+def _evaluate(components, feature, notification: HIDPPNotification, device, result) -> Any:
     res = True
     for component in components:
         res = component.evaluate(feature, notification, device, result)
@@ -538,12 +544,12 @@ class Rule(RuleComponent):
         source = "(" + self.source + ")" if self.source else ""
         return f"Rule{source}[{', '.join([c.__str__() for c in self.components])}]"
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate rule: %s", self)
         return _evaluate(self.components, feature, notification, device, True)
 
-    def once(self, feature, notification, device, last_result):
+    def once(self, feature, notification: HIDPPNotification, device, last_result):
         self.evaluate(feature, notification, device, last_result)
         return False
 
@@ -558,7 +564,7 @@ class Condition(RuleComponent):
     def __str__(self):
         return "CONDITION"
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return False
@@ -574,7 +580,7 @@ class Not(Condition):
     def __str__(self):
         return "Not: " + str(self.component)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         result = self.component.evaluate(feature, notification, device, last_result)
@@ -591,7 +597,7 @@ class Or(Condition):
     def __str__(self):
         return "Or: [" + ", ".join(str(c) for c in self.components) + "]"
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         result = False
@@ -614,7 +620,7 @@ class And(Condition):
     def __str__(self):
         return "And: [" + ", ".join(str(c) for c in self.components) + "]"
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return _evaluate(self.components, feature, notification, device, last_result)
@@ -687,7 +693,7 @@ class Process(Condition):
     def __str__(self):
         return "Process: " + str(self.process)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         if not isinstance(self.process, str):
@@ -718,7 +724,7 @@ class MouseProcess(Condition):
     def __str__(self):
         return "MouseProcess: " + str(self.process)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         if not isinstance(self.process, str):
@@ -742,7 +748,7 @@ class Feature(Condition):
     def __str__(self):
         return "Feature: " + str(self.feature)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return feature == self.feature
@@ -763,7 +769,7 @@ class Report(Condition):
     def __str__(self):
         return "Report: " + str(self.report)
 
-    def evaluate(self, report, notification, device, last_result):
+    def evaluate(self, report, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return (notification.address >> 4) == self.report
@@ -785,7 +791,7 @@ class Setting(Condition):
     def __str__(self):
         return "Setting: " + " ".join([str(a) for a in self.args])
 
-    def evaluate(self, report, notification, device, last_result):
+    def evaluate(self, report, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         if len(self.args) < 3:
@@ -836,7 +842,7 @@ class Modifiers(Condition):
     def __str__(self):
         return "Modifiers: " + str(self.desired)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         if gkeymap:
@@ -896,7 +902,7 @@ class Key(Condition):
     def __str__(self):
         return f"Key: {str(self.key) if self.key else 'None'} ({self.action})"
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return bool(self.key and self.key == (key_down if self.action == self.DOWN else key_up))
@@ -928,7 +934,7 @@ class KeyIsDown(Condition):
     def __str__(self):
         return f"KeyIsDown: {str(self.key) if self.key else 'None'}"
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return key_is_down(self.key)
@@ -982,7 +988,7 @@ class Test(Condition):
     def __str__(self):
         return "Test: " + str(self.test)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return self.function(feature, notification.address, notification.data, self.parameter)
@@ -1010,7 +1016,7 @@ class TestBytes(Condition):
     def __str__(self):
         return "TestBytes: " + str(self.test)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return self.function(feature, notification.address, notification.data)
@@ -1043,7 +1049,7 @@ class MouseGesture(Condition):
     def __str__(self):
         return "MouseGesture: " + " ".join(self.movements)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         if feature == FEATURE.MOUSE_GESTURE:
@@ -1085,7 +1091,7 @@ class Active(Condition):
     def __str__(self):
         return "Active: " + str(self.devID)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         dev = device.find(self.devID)
@@ -1106,7 +1112,7 @@ class Device(Condition):
     def __str__(self):
         return "Device: " + str(self.devID)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         return device.unitId == self.devID or device.serial == self.devID
@@ -1126,7 +1132,7 @@ class Host(Condition):
     def __str__(self):
         return "Host: " + str(self.host)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.DEBUG):
             logger.debug("evaluate condition: %s", self)
         hostname = socket.getfqdn()
@@ -1140,7 +1146,7 @@ class Action(RuleComponent):
     def __init__(self, *args):
         pass
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         return None
 
 
@@ -1227,7 +1233,7 @@ class KeyPress(Action):
                 simulate_key(keycode, _KEY_RELEASE)
                 self.mods(level, modifiers, _KEY_RELEASE)
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if gkeymap:
             current = gkeymap.get_modifier_state()
             if logger.isEnabledFor(logging.INFO):
@@ -1253,10 +1259,10 @@ class KeyPress(Action):
 
 # KeyDown is dangerous as the key can auto-repeat and make your system unusable
 # class KeyDown(KeyPress):
-#    def evaluate(self, feature, notification, device, last_result):
+#    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
 #        super().keyDown(self.keys, current_key_modifiers)
 # class KeyUp(KeyPress):
-#    def evaluate(self, feature, notification, device, last_result):
+#    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
 #        super().keyUp(self.keys, current_key_modifiers)
 
 
@@ -1273,7 +1279,7 @@ class MouseScroll(Action):
     def __str__(self):
         return "MouseScroll: " + " ".join([str(a) for a in self.amounts])
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         amounts = self.amounts
         if isinstance(last_result, numbers.Number):
             amounts = [math.floor(last_result * a) for a in self.amounts]
@@ -1315,7 +1321,7 @@ class MouseClick(Action):
     def __str__(self):
         return f"MouseClick: {self.button} ({int(self.count)})"
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.INFO):
             logger.info(f"MouseClick action: {int(self.count)} {self.button}")
         if self.button and self.count:
@@ -1339,7 +1345,7 @@ class Set(Action):
     def __str__(self):
         return "Set: " + " ".join([str(a) for a in self.args])
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if len(self.args) < 3:
             return None
         if logger.isEnabledFor(logging.INFO):
@@ -1387,7 +1393,7 @@ class Execute(Action):
     def __str__(self):
         return "Execute: " + " ".join([a for a in self.args])
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if logger.isEnabledFor(logging.INFO):
             logger.info("Execute action: %s", self.args)
         subprocess.Popen(self.args)
@@ -1418,7 +1424,7 @@ class Later(Action):
     def __str__(self):
         return "Later: [" + str(self.delay) + ", " + ", ".join(str(c) for c in self.components) + "]"
 
-    def evaluate(self, feature, notification, device, last_result):
+    def evaluate(self, feature, notification: HIDPPNotification, device, last_result):
         if self.delay and self.rule:
             if self.delay >= 1:
                 GLib.timeout_add_seconds(int(self.delay), Rule.once, self.rule, feature, notification, device, last_result)
@@ -1483,14 +1489,14 @@ def key_is_down(key):
         return key in keys_down
 
 
-def evaluate_rules(feature, notification, device):
+def evaluate_rules(feature, notification: HIDPPNotification, device):
     if logger.isEnabledFor(logging.DEBUG):
         logger.debug("evaluating rules on %s", notification)
     rules.evaluate(feature, notification, device, True)
 
 
 # process a notification
-def process_notification(device, notification, feature):
+def process_notification(device, notification: HIDPPNotification, feature):
     global keys_down, g_keys_down, m_keys_down, mr_key_down, key_down, key_up, thumb_wheel_displacement
     key_down, key_up = None, None
     # need to keep track of keys that are down to find a new key down
@@ -1544,7 +1550,7 @@ _file_path = os.path.join(_XDG_CONFIG_HOME, "solaar", "rules.yaml")
 rules = built_in_rules
 
 
-def _save_config_rule_file(file_name=_file_path):
+def _save_config_rule_file(file_name: str = _file_path, rule_list: list[Rule] = rules.components):
     # This is a trick to show str/float/int lists in-line (inspired by https://stackoverflow.com/a/14001707)
     class inline_list(list):
         pass
@@ -1577,18 +1583,18 @@ def _save_config_rule_file(file_name=_file_path):
         # 'version': (1, 3),  # it would be printed for every rule
     }
     # Save only user-defined rules
-    rules_to_save = sum((r.data()["Rule"] for r in rules.components if r.source == file_name), [])
-    if True:  # save even if there are no rules to save
-        if logger.isEnabledFor(logging.INFO):
-            logger.info("saving %d rule(s) to %s", len(rules_to_save), file_name)
-        try:
-            with open(file_name, "w") as f:
-                if rules_to_save:
-                    f.write("%YAML 1.3\n")  # Write version manually
-                yaml.dump_all(convert([r["Rule"] for r in rules_to_save]), f, **dump_settings)
-        except Exception as e:
-            logger.error("failed to save to %s\n%s", file_name, e)
-            return False
+    rules_to_save = sum((r.data()["Rule"] for r in rule_list if r.source == file_name), [])
+    if logger.isEnabledFor(logging.INFO):
+        logger.info("saving %d rule(s) to %s", len(rules_to_save), file_name)
+    try:
+        with open(file_name, "w") as f:
+            if rules_to_save:
+                f.write("%YAML 1.3\n")  # Write version manually
+            dump_data = [r["Rule"] for r in rules_to_save]
+            yaml.dump_all(convert(dump_data), f, **dump_settings)
+    except Exception as e:
+        logger.error("failed to save to %s\n%s", file_name, e)
+        return False
     return True
 
 
diff --git a/lib/solaar/ui/diversion_rules.py b/lib/solaar/ui/diversion_rules.py
index 17431a33..6621f39b 100644
--- a/lib/solaar/ui/diversion_rules.py
+++ b/lib/solaar/ui/diversion_rules.py
@@ -973,7 +973,7 @@ class DeviceInfoFactory:
 
 class AllDevicesInfo:
     def __init__(self):
-        self._devices = []
+        self._devices: list[DeviceInfo] = []
         self._lock = threading.Lock()
 
     def __iter__(self):