diff --git a/src/mqtt/HomeAssistantMqttHandler.cpp b/src/mqtt/HomeAssistantMqttHandler.cpp
index 823923ca..3987e752 100644
--- a/src/mqtt/HomeAssistantMqttHandler.cpp
+++ b/src/mqtt/HomeAssistantMqttHandler.cpp
@@ -215,11 +215,11 @@ bool HomeAssistantMqttHandler::publishSystem(HwTools* hw) {
         for(int i=0;i<sensors;i++){
             snprintf_P(json, BufferSize, HADISCOVER_JSON,
                 FPSTR(HA_NAMES[i]),
-                topic, FPSTR(HA_TOPICS[i]),
-                haUID, FPSTR(HA_PARAMS[i]),
-                haUID, FPSTR(HA_PARAMS[i]),
+                topic.c_str(), FPSTR(HA_TOPICS[i]),
+                haUID.c_str(), FPSTR(HA_PARAMS[i]),
+                haUID.c_str(), FPSTR(HA_PARAMS[i]),
                 FPSTR(HA_UOM[i]),
-                FPSTR(HA_PARAMS[i]), FPSTR(HA_PARAMS[i]), haUID, FPSTR(HA_PARAMS[i]),
+                FPSTR(HA_PARAMS[i]), FPSTR(HA_PARAMS[i]), haUID.c_str(), FPSTR(HA_PARAMS[i]),
                 FPSTR(HA_DEVCL[i]),
                 haUID.c_str(),
                 haName.c_str(),