diff --git a/homeassistant/components/google_assistant/const.py b/homeassistant/components/google_assistant/const.py
index a19707bffbc7..339cddae883e 100644
--- a/homeassistant/components/google_assistant/const.py
+++ b/homeassistant/components/google_assistant/const.py
@@ -86,6 +86,7 @@ TYPE_SPEAKER = f"{PREFIX_TYPES}SPEAKER"
 TYPE_SWITCH = f"{PREFIX_TYPES}SWITCH"
 TYPE_THERMOSTAT = f"{PREFIX_TYPES}THERMOSTAT"
 TYPE_TV = f"{PREFIX_TYPES}TV"
+TYPE_WINDOW = f"{PREFIX_TYPES}WINDOW"
 TYPE_VACUUM = f"{PREFIX_TYPES}VACUUM"
 
 SERVICE_REQUEST_SYNC = "request_sync"
@@ -147,7 +148,7 @@ DEVICE_CLASS_TO_GOOGLE_TYPES = {
     (binary_sensor.DOMAIN, binary_sensor.BinarySensorDeviceClass.DOOR): TYPE_DOOR,
     (binary_sensor.DOMAIN, binary_sensor.BinarySensorDeviceClass.LOCK): TYPE_SENSOR,
     (binary_sensor.DOMAIN, binary_sensor.BinarySensorDeviceClass.OPENING): TYPE_SENSOR,
-    (binary_sensor.DOMAIN, binary_sensor.BinarySensorDeviceClass.WINDOW): TYPE_SENSOR,
+    (binary_sensor.DOMAIN, binary_sensor.BinarySensorDeviceClass.WINDOW): TYPE_WINDOW,
     (
         binary_sensor.DOMAIN,
         binary_sensor.BinarySensorDeviceClass.GARAGE_DOOR,
diff --git a/tests/components/google_assistant/test_smart_home.py b/tests/components/google_assistant/test_smart_home.py
index 4b11910999a7..684a6db26408 100644
--- a/tests/components/google_assistant/test_smart_home.py
+++ b/tests/components/google_assistant/test_smart_home.py
@@ -1026,7 +1026,7 @@ async def test_device_class_switch(hass, device_class, google_type):
         ("garage_door", "action.devices.types.GARAGE"),
         ("lock", "action.devices.types.SENSOR"),
         ("opening", "action.devices.types.SENSOR"),
-        ("window", "action.devices.types.SENSOR"),
+        ("window", "action.devices.types.WINDOW"),
     ],
 )
 async def test_device_class_binary_sensor(hass, device_class, google_type):