diff --git a/homeassistant/components/gatus/binary_sensor.py b/homeassistant/components/gatus/binary_sensor.py
index 73abc4b6d7b6..2ad0cf7c7d00 100644
--- a/homeassistant/components/gatus/binary_sensor.py
+++ b/homeassistant/components/gatus/binary_sensor.py
@@ -1,6 +1,6 @@
 """Support for Gatus binary sensors."""
 
-from typing import override
+from typing import TYPE_CHECKING, override
 
 from homeassistant.components.binary_sensor import (
     BinarySensorDeviceClass,
@@ -59,10 +59,9 @@ class GatusEndpointBinarySensor(GatusEndpointEntity, BinarySensorEntity):
 
     @property
     @override
-    def is_on(self) -> bool | None:
+    def is_on(self) -> bool:
         """Return true if the endpoint is up and healthy."""
-        latest_result = self.latest_result
-        if latest_result is None:
-            return None
+        if TYPE_CHECKING:
+            assert self.latest_result is not None
 
-        return latest_result.success
+        return self.latest_result.success
diff --git a/tests/components/gatus/test_binary_sensor.py b/tests/components/gatus/test_binary_sensor.py
index bc2565915cbc..c28a61f5742d 100644
--- a/tests/components/gatus/test_binary_sensor.py
+++ b/tests/components/gatus/test_binary_sensor.py
@@ -7,7 +7,7 @@ from freezegun.api import FrozenDateTimeFactory
 from gatus_api import EndpointStatus, GatusClientError, Result
 from syrupy.assertion import SnapshotAssertion
 
-from homeassistant.const import Platform
+from homeassistant.const import STATE_OFF, STATE_ON, STATE_UNAVAILABLE, Platform
 from homeassistant.core import HomeAssistant
 from homeassistant.helpers import entity_registry as er
 
@@ -65,7 +65,7 @@ async def test_binary_sensor_dynamic_update(
     await setup_integration(hass, mock_config_entry)
     state = hass.states.get("binary_sensor.core_backend_service")
     assert state is not None
-    assert state.state == "on"
+    assert state.state == STATE_ON
 
     mock_data = await async_load_json_array_fixture(hass, "gatus/group.json")
 
@@ -78,7 +78,7 @@ async def test_binary_sensor_dynamic_update(
     await hass.async_block_till_done()
 
     state = hass.states.get("binary_sensor.core_backend_service")
-    assert state.state == "off"
+    assert state.state == STATE_OFF
 
 
 async def test_binary_sensor_no_group(
@@ -97,7 +97,7 @@ async def test_binary_sensor_no_group(
 
     state = hass.states.get("binary_sensor.backend_service")
     assert state is not None
-    assert state.state == "on"
+    assert state.state == STATE_ON
 
 
 async def test_binary_sensor_client_error(
@@ -110,7 +110,7 @@ async def test_binary_sensor_client_error(
     await setup_integration(hass, mock_config_entry)
     state = hass.states.get("binary_sensor.core_backend_service")
     assert state is not None
-    assert state.state == "on"
+    assert state.state == STATE_ON
 
     mock_gatus_client.get_endpoints_statuses.side_effect = GatusClientError
 
@@ -119,7 +119,7 @@ async def test_binary_sensor_client_error(
     await hass.async_block_till_done()
 
     state = hass.states.get("binary_sensor.core_backend_service")
-    assert state.state == "unavailable"
+    assert state.state == STATE_UNAVAILABLE
 
 
 async def test_binary_sensor_empty_results(
@@ -141,7 +141,7 @@ async def test_binary_sensor_empty_results(
 
     state = hass.states.get("binary_sensor.backend_service")
     assert state is not None
-    assert state.state == "unavailable"
+    assert state.state == STATE_UNAVAILABLE
 
 
 async def test_binary_sensor_missing_status(
@@ -163,7 +163,7 @@ async def test_binary_sensor_missing_status(
 
     state = hass.states.get("binary_sensor.backend_service")
     assert state is not None
-    assert state.state == "off"
+    assert state.state == STATE_OFF
 
 
 async def test_binary_sensor_dynamic_endpoints(