diff --git a/custom_components/octopus_energy/sensor.py b/custom_components/octopus_energy/sensor.py
index 348d345e..797ecb15 100644
--- a/custom_components/octopus_energy/sensor.py
+++ b/custom_components/octopus_energy/sensor.py
@@ -419,7 +419,7 @@ async def async_setup_default_sensors(hass: HomeAssistant, config, async_add_ent
           entities.append(OctopusEnergyCurrentRatesDataLastRetrieved(hass, gas_rate_coordinator, False, meter, point))
           entities.append(OctopusEnergyCurrentStandingChargeDataLastRetrieved(hass, gas_standing_charges_coordinator, False, meter, point))
 
-          debug_override = await async_get_debug_override(hass, mpan, serial_number)
+          debug_override = await async_get_debug_override(hass, mprn, serial_number)
           previous_consumption_coordinator = await async_create_previous_consumption_and_rates_coordinator(
             hass,
             account_id,