diff --git a/CHANGELOG.md b/CHANGELOG.md
index 61b8e1d8854cc79d4937720acfc153d2663fc806..8b5b722b22458929f474b4ca2829743725ae4125 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added a tutorial for the edit mode to the documentation
 
 ### Changed (for changes in existing functionality)
+- Updated from bootstrap 3 to bootstrap 5. This is a major change which will
+  possibly break existing custom implementations (e.g. a custom welcome page)
+  since a lot of classes where renamed by bootstrap an other classes have been
+  dropped entirely (e.g. "jumbotron"). Please have a look at
+    * https://getbootstrap.com/docs/5.0/migration/
+    * https://getbootstrap.com/docs/4.6/migration/
 - The heading attributes datatype, path, checksum and size are now placed 
   in a `details` html element.