diff --git a/examples/mqtt.py b/examples/mqtt.py
index 1e44ebf..433a44a 100644
--- a/examples/mqtt.py
+++ b/examples/mqtt.py
@@ -95,19 +95,19 @@ def on_connect(client, userdata, flags, rc):
 
 def on_message(client, userdata, msg):
     if msg.topic == "openWB/pv/W":
-        value_pvProduction = msg.payload.decode()
+        value_pvProduction = ""+msg.payload.decode()
         line = 0
     elif msg.topic == "openWB/global/WHouseConsumption":
-        value_wHouseConsumption = msg.payload.decode()
+        value_wHouseConsumption = ""+msg.payload.decode()
         line = 15
     elif msg.topic == "openWB/evu/W":
-        value_energyImportExport = msg.payload.decode()
+        value_energyImportExport = ""+msg.payload.decode()
         line = 30
     elif msg.topic == "openWB/housebattery/%Soc":
-        topic_houseBatterySoC = msg.payload.decode()
+        topic_houseBatterySoC = ""+msg.payload.decode()
         line = 45
     elif msg.topic == "openWB/housebattery/W":  
-        topic_houseBatteryLoadUnload = msg.payload.decode()  
+        topic_houseBatteryLoadUnload = ""+msg.payload.decode()  
         line = 60
 
     print(line)