diff --git a/homeassistant/components/zwave/light.py b/homeassistant/components/zwave/light.py
index 244b4a557e1ee38da8ac386d4002d5dfdf8353ce..52014e37eea27807e1563ba005b6475c1d34dc1e 100644
--- a/homeassistant/components/zwave/light.py
+++ b/homeassistant/components/zwave/light.py
@@ -175,7 +175,7 @@ class ZwaveDimmer(ZWaveDeviceEntity, LightEntity):
                     self._refreshing = True
                     self.values.primary.refresh()
 
-                if self._timer is not None and self._timer.isAlive():
+                if self._timer is not None and self._timer.is_alive():
                     self._timer.cancel()
 
                 self._timer = Timer(self._delay, _refresh_value)