diff --git a/homeassistant/components/integration/sensor.py b/homeassistant/components/integration/sensor.py
index c0e4a723515..250d10cd9c4 100644
--- a/homeassistant/components/integration/sensor.py
+++ b/homeassistant/components/integration/sensor.py
@@ -106,7 +106,7 @@ class IntegrationSensor(RestoreEntity, SensorEntity):
         """Initialize the integration sensor."""
         self._sensor_source_id = source_entity
         self._round_digits = round_digits
-        self._state = STATE_UNAVAILABLE
+        self._state = None
         self._method = integration_method
 
         self._name = name if name is not None else f"{source_entity} integral"
diff --git a/tests/components/integration/test_sensor.py b/tests/components/integration/test_sensor.py
index 354f4af95ba..03a43fd2c66 100644
--- a/tests/components/integration/test_sensor.py
+++ b/tests/components/integration/test_sensor.py
@@ -123,7 +123,7 @@ async def test_restore_state_failed(hass: HomeAssistant) -> None:
 
     state = hass.states.get("sensor.integration")
     assert state
-    assert state.state == "unavailable"
+    assert state.state == "unknown"
     assert state.attributes.get("unit_of_measurement") is None
     assert state.attributes.get("state_class") == STATE_CLASS_TOTAL