diff --git a/src/glossary.md b/src/glossary.md
index 83bb519..73c7bca 100644
--- a/src/glossary.md
+++ b/src/glossary.md
@@ -793,7 +793,7 @@ system security, resilience, connectivity, maintainability and usability.
 
 The concept of a system layer has only been recently recognised—the term itself was [coined by
 Benno Rice in a 2019 conference
-presentation](https://2019.linux.conf.au/schedule/presentation/156/)—although many of the ideas
+presentation](https://www.youtube.com/watch?v=o_AIw9bGogo)—although many of the ideas
 it entails have a long history.
 
 The hypothesis that the Synit system explores is that the [Syndicated Actor model][] provides a