diff --git a/homeassistant/components/generic_hygrostat/humidifier.py b/homeassistant/components/generic_hygrostat/humidifier.py
index 8ed2711d7cd..dfd6be14e6a 100644
--- a/homeassistant/components/generic_hygrostat/humidifier.py
+++ b/homeassistant/components/generic_hygrostat/humidifier.py
@@ -436,7 +436,7 @@ class GenericHygrostat(HumidifierEntity, RestoreEntity):
         data = {ATTR_ENTITY_ID: self._switch_entity_id}
         await self.hass.services.async_call(HA_DOMAIN, SERVICE_TURN_OFF, data)
 
-    async def async_set_mode(self, mode: str):
+    async def async_set_mode(self, mode: str) -> None:
         """Set new mode.
 
         This method must be run in the event loop and returns a coroutine.
diff --git a/homeassistant/components/xiaomi_miio/humidifier.py b/homeassistant/components/xiaomi_miio/humidifier.py
index 50e0cd8c72d..6fde33309e4 100644
--- a/homeassistant/components/xiaomi_miio/humidifier.py
+++ b/homeassistant/components/xiaomi_miio/humidifier.py
@@ -1,6 +1,7 @@
 """Support for Xiaomi Mi Air Purifier and Xiaomi Mi Air Humidifier with humidifier entity."""
 import logging
 import math
+from typing import Any
 
 from miio.integrations.humidifier.deerma.airhumidifier_mjjsq import (
     OperationMode as AirhumidifierMjjsqOperationMode,
@@ -136,10 +137,7 @@ class XiaomiGenericHumidifier(XiaomiCoordinatedMiioEntity, HumidifierEntity):
         """Get the current mode."""
         return self._mode
 
-    async def async_turn_on(
-        self,
-        **kwargs,
-    ) -> None:
+    async def async_turn_on(self, **kwargs: Any) -> None:
         """Turn the device on."""
         result = await self._try_command(
             "Turning the miio device on failed.", self._device.on
@@ -148,7 +146,7 @@ class XiaomiGenericHumidifier(XiaomiCoordinatedMiioEntity, HumidifierEntity):
             self._state = True
             self.async_write_ha_state()
 
-    async def async_turn_off(self, **kwargs) -> None:
+    async def async_turn_off(self, **kwargs: Any) -> None:
         """Turn the device off."""
         result = await self._try_command(
             "Turning the miio device off failed.", self._device.off