diff --git a/custom_components/hsem/custom_sensors/avg_sensor.py b/custom_components/hsem/custom_sensors/avg_sensor.py
index 316d13e..77eafb1 100644
--- a/custom_components/hsem/custom_sensors/avg_sensor.py
+++ b/custom_components/hsem/custom_sensors/avg_sensor.py
@@ -173,7 +173,10 @@ async def _async_store_utility_meter_value(self) -> None:
         except Exception:
             utility_meter_value = None
 
-        if utility_meter_value is not None and self._measurements is not None:
+        if self._measurements is None:
+            self._measurements = {}
+
+        if utility_meter_value is not None:
             self._measurements[current_date.isoformat()] = round(
                 float(utility_meter_value), 2
             )