diff --git a/ecowitt2mqtt/config.py b/ecowitt2mqtt/config.py
index ee0d9894..1a9f6e77 100644
--- a/ecowitt2mqtt/config.py
+++ b/ecowitt2mqtt/config.py
@@ -225,7 +225,7 @@ def validate_mqtt_auth(cls, data: dict[str, Any]) -> dict[str, Any]:
         if (data.get(CONF_MQTT_USERNAME) is None) != (
             data.get(CONF_MQTT_PASSWORD) is None
         ):
-            raise ValueError("MQTT auth must be both fully present or fully absent")
+            raise ValueError("Invalid MQTT auth configuration")
         return data
 
     validate_mqtt_retain = field_validator("mqtt_retain", mode="before")(