diff --git a/modules/base_plugins/dummy_temp/__init__.py b/modules/base_plugins/dummy_temp/__init__.py
index c5f0478..bc81d85 100644
--- a/modules/base_plugins/dummy_temp/__init__.py
+++ b/modules/base_plugins/dummy_temp/__init__.py
@@ -48,7 +48,7 @@ class DummyTempSensor(SensorActive):
         """
         toogle inc from up/down
         """
-        self.inc *= -1
+        self.inc = float(self.inc) * -1
 
     def stop(self):
         """