diff --git a/source/_docs/automation/trigger.markdown b/source/_docs/automation/trigger.markdown
index 32afab597a9..efa40b6cfde 100644
--- a/source/_docs/automation/trigger.markdown
+++ b/source/_docs/automation/trigger.markdown
@@ -293,7 +293,7 @@ automation:
 
 ### Time pattern trigger
 
-With the time pattern trigger, you can match if the hour, minute or second of the current time matches a specific value. You can prefix the value with a `/` to match whenever the value is divisible by that number. You can specify `*` to match any value.
+With the time pattern trigger, you can match if the hour, minute or second of the current time matches a specific value. You can prefix the value with a `/` to match whenever the value is divisible by that number. You can specify `*` to match any value (when using the web interface this is required, the fields cannot be left empty).
 
 ```yaml
 automation: