diff --git a/src/dallassensor.cpp b/src/dallassensor.cpp
index ba09c7cfe..a81975d35 100644
--- a/src/dallassensor.cpp
+++ b/src/dallassensor.cpp
@@ -387,7 +387,7 @@ void DallasSensor::publish_values(const bool force) {
                     // use '_' as HA doesn't like '-' in the topic name
                     std::string topicname = sensor.to_string();
                     std::replace(topicname.begin(), topicname.end(), '-', '_');
-                    snprintf_P(topic, sizeof(topic), PSTR("homeassistant/sensor/%s/dallas_sensor%s/config"), Mqtt::base().c_str(), topicname);
+                    snprintf_P(topic, sizeof(topic), PSTR("homeassistant/sensor/%s/dallas_sensor%s/config"), Mqtt::base().c_str(), topicname.c_str());
                 } else {
                     snprintf_P(topic, sizeof(topic), PSTR("homeassistant/sensor/%s/dallas_sensor%d/config"), Mqtt::base().c_str(), sensor_no);
                 }