diff --git a/homeassistant/components/harmony/select.py b/homeassistant/components/harmony/select.py
index e19f6c3bc9c..3728c4b17a4 100644
--- a/homeassistant/components/harmony/select.py
+++ b/homeassistant/components/harmony/select.py
@@ -40,7 +40,7 @@ class HarmonyActivitySelect(HarmonyEntity, SelectEntity):
         self._attr_name = name
 
     @property
-    def icon(self):
+    def icon(self) -> str:
         """Return a representative icon."""
         if not self.available or self.current_option == ACTIVITY_POWER_OFF:
             return "mdi:remote-tv-off"
@@ -52,7 +52,7 @@ class HarmonyActivitySelect(HarmonyEntity, SelectEntity):
         return [ACTIVITY_POWER_OFF] + sorted(self._data.activity_names)
 
     @property
-    def current_option(self):
+    def current_option(self) -> str | None:
         """Return the current activity."""
         _, activity_name = self._data.current_activity
         return activity_name
@@ -61,18 +61,19 @@ class HarmonyActivitySelect(HarmonyEntity, SelectEntity):
         """Change the current activity."""
         await self._data.async_start_activity(option)
 
-    async def async_added_to_hass(self):
+    async def async_added_to_hass(self) -> None:
         """Call when entity is added to hass."""
-
-        callbacks = {
-            "connected": self.async_got_connected,
-            "disconnected": self.async_got_disconnected,
-            "activity_starting": self._async_activity_update,
-            "activity_started": self._async_activity_update,
-            "config_updated": None,
-        }
-
-        self.async_on_remove(self._data.async_subscribe(HarmonyCallback(**callbacks)))
+        self.async_on_remove(
+            self._data.async_subscribe(
+                HarmonyCallback(
+                    connected=self.async_got_connected,
+                    disconnected=self.async_got_disconnected,
+                    activity_starting=self._async_activity_update,
+                    activity_started=self._async_activity_update,
+                    config_updated=None,
+                )
+            )
+        )
 
     @callback
     def _async_activity_update(self, activity_info: tuple):
diff --git a/homeassistant/components/harmony/subscriber.py b/homeassistant/components/harmony/subscriber.py
index 2731d8555f0..efb46f5c6e6 100644
--- a/homeassistant/components/harmony/subscriber.py
+++ b/homeassistant/components/harmony/subscriber.py
@@ -7,12 +7,12 @@ import logging
 # https://bugs.python.org/issue42965
 from typing import Any, Callable, NamedTuple, Optional
 
-from homeassistant.core import callback
+from homeassistant.core import CALLBACK_TYPE, HomeAssistant, callback
 
 _LOGGER = logging.getLogger(__name__)
 
-NoParamCallback = Optional[Callable[[object], Any]]
-ActivityCallback = Optional[Callable[[object, tuple], Any]]
+NoParamCallback = Optional[Callable[[], Any]]
+ActivityCallback = Optional[Callable[[tuple], Any]]
 
 
 class HarmonyCallback(NamedTuple):
@@ -28,11 +28,11 @@ class HarmonyCallback(NamedTuple):
 class HarmonySubscriberMixin:
     """Base implementation for a subscriber."""
 
-    def __init__(self, hass):
+    def __init__(self, hass: HomeAssistant) -> None:
         """Initialize an subscriber."""
         super().__init__()
         self._hass = hass
-        self._subscriptions = []
+        self._subscriptions: list[HarmonyCallback] = []
         self._activity_lock = asyncio.Lock()
 
     async def async_lock_start_activity(self):
@@ -40,23 +40,23 @@ class HarmonySubscriberMixin:
         await self._activity_lock.acquire()
 
     @callback
-    def async_unlock_start_activity(self):
+    def async_unlock_start_activity(self) -> None:
         """Release the lock."""
         if self._activity_lock.locked():
             self._activity_lock.release()
 
     @callback
-    def async_subscribe(self, update_callbacks: HarmonyCallback) -> Callable:
+    def async_subscribe(self, update_callbacks: HarmonyCallback) -> CALLBACK_TYPE:
         """Add a callback subscriber."""
         self._subscriptions.append(update_callbacks)
 
-        def _unsubscribe():
+        def _unsubscribe() -> None:
             self.async_unsubscribe(update_callbacks)
 
         return _unsubscribe
 
     @callback
-    def async_unsubscribe(self, update_callback: HarmonyCallback):
+    def async_unsubscribe(self, update_callback: HarmonyCallback) -> None:
         """Remove a callback subscriber."""
         self._subscriptions.remove(update_callback)
 
@@ -85,7 +85,7 @@ class HarmonySubscriberMixin:
         self.async_unlock_start_activity()
         self._call_callbacks("activity_started", activity_info)
 
-    def _call_callbacks(self, callback_func_name: str, argument: tuple = None):
+    def _call_callbacks(self, callback_func_name: str, argument: tuple = None) -> None:
         for subscription in self._subscriptions:
             current_callback = getattr(subscription, callback_func_name)
             if current_callback: