diff --git a/source/_posts/2019-09-13-live-blogging-symfonylive-london.md b/source/_posts/2019-09-13-live-blogging-symfonylive-london.md
index 3b0a1ec2..c0b91716 100644
--- a/source/_posts/2019-09-13-live-blogging-symfonylive-london.md
+++ b/source/_posts/2019-09-13-live-blogging-symfonylive-london.md
@@ -138,3 +138,4 @@ Notifier
 * `composer req symfony/messager` - best MessageBus implementation
 * Message -> Message bus -> Message handler
 * Message is a plain PHP class
+* Handler is a normal PHP class which is invokable