diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7dc20069..bef711ad 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,7 +12,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 
 ### Changed
 
-- Upgrade to Mermaid v9.1.3
+- Upgrade to Mermaid v9.1.3 ([#233](https://github.com/jpanther/congo/pull/233))
 
 ### Fixed