diff --git a/home-assistant.conf.default b/home-assistant.conf.default
index 4bcfdc5cb79..b90eaee1d4b 100644
--- a/home-assistant.conf.default
+++ b/home-assistant.conf.default
@@ -27,7 +27,7 @@ download_dir=downloads
 
 [device_sun_light_trigger]
 # Example how you can specify a specific group that has to be turned on
-# light_group=living_room
+# light_group=group.living_room
 
 # A comma seperated list of states that have to be tracked
 # As a single group
diff --git a/homeassistant/components/group.py b/homeassistant/components/group.py
index fc2b0fd4148..6d8d208af40 100644
--- a/homeassistant/components/group.py
+++ b/homeassistant/components/group.py
@@ -47,9 +47,9 @@ def is_on(statemachine, group):
         return False
 
 
-def get_categories(statemachine, group_name):
+def get_categories(statemachine, group):
     """ Get the categories that make up this group. """
-    state = statemachine.get_state(STATE_CATEGORY_FORMAT.format(group_name))
+    state = statemachine.get_state(group)
 
     return state['attributes'][STATE_ATTR_CATEGORIES] if state else []