diff --git a/source/_docs/configuration/templating.markdown b/source/_docs/configuration/templating.markdown
index 38407aabd138..6668c9d08863 100644
--- a/source/_docs/configuration/templating.markdown
+++ b/source/_docs/configuration/templating.markdown
@@ -57,7 +57,7 @@ Extensions allow templates to access all of the Home Assistant specific states a
 - `states('device_tracker.paulus')` will return the state string (not the object) of the given entity or `unknown` if it doesn't exist.
 - `is_state('device_tracker.paulus', 'home')` will test if the given entity is the specified state.
 - `state_attr('device_tracker.paulus', 'battery')` will return the value of the attribute or None if it doesn't exist.
-- `is_state_attr('device_tracker.paulus', 'battery', 40)` will test if the given entity attribute is the specified state (in this case, a numeric value).
+- `is_state_attr('device_tracker.paulus', 'battery', 40)` will test if the given entity attribute is the specified state (in this case, a numeric value). Note that the attribute can be `None` and you want to check if it is `None`, you need to use `state_attr('sensor.my_sensor', 'attr') == None`. 
 
 <div class='note warning'>