diff --git a/homeassistant/components/homematic/__init__.py b/homeassistant/components/homematic/__init__.py
index 527b8c8f0186f..53c8e26701615 100644
--- a/homeassistant/components/homematic/__init__.py
+++ b/homeassistant/components/homematic/__init__.py
@@ -869,7 +869,7 @@ def _hm_event_callback(self, device, caller, attribute, value):
 
         # Availability has changed
         if attribute == 'UNREACH':
-            self._available = bool(value)
+            self._available = not bool(value)
             has_changed = True
         elif not self.available:
             self._available = False