diff --git a/homeassistant/components/wsdot/sensor.py b/homeassistant/components/wsdot/sensor.py
index 3aae6746ea9..73714b75c95 100644
--- a/homeassistant/components/wsdot/sensor.py
+++ b/homeassistant/components/wsdot/sensor.py
@@ -6,6 +6,7 @@ from datetime import datetime, timedelta, timezone
 from http import HTTPStatus
 import logging
 import re
+from typing import Any
 
 import requests
 import voluptuous as vol
@@ -125,7 +126,7 @@ class WashingtonStateTravelTimeSensor(WashingtonStateTransportSensor):
         self._state = self._data.get(ATTR_CURRENT_TIME)
 
     @property
-    def extra_state_attributes(self):
+    def extra_state_attributes(self) -> dict[str, Any] | None:
         """Return other details about the sensor state."""
         if self._data is not None:
             attrs = {}
@@ -140,6 +141,7 @@ class WashingtonStateTravelTimeSensor(WashingtonStateTransportSensor):
                 self._data.get(ATTR_TIME_UPDATED)
             )
             return attrs
+        return None
 
 
 def _parse_wsdot_timestamp(timestamp):