diff --git a/examples/mqtt.py b/examples/mqtt.py
index 03e3cc7..1e44ebf 100644
--- a/examples/mqtt.py
+++ b/examples/mqtt.py
@@ -31,6 +31,12 @@ username = "mqtt-user"
 pw = "phio6yiR9ohs1veeghu4WaeGhaiRi8he4EiWasheev4faeku8tohdiuthah7zahP"
 client_id = "solarmonitor"
 
+global value_pvProduction
+global value_wHouseConsumption
+global value_energyImportExport
+global value_houseBatterySoC
+global value_houseBatteryLoadUnload
+
 value_pvProduction = "0"
 value_wHouseConsumption = "0"
 value_energyImportExport = "0"