diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 76f684bd07..6f6ec88f29 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -20,6 +20,7 @@ Changelog
  * Maintenance: Adjust Eslint rules for TypeScript files (Karthik Ayangar)
  * Maintenance: Rename the React `Button` that only renders links (a element) to `Link` and remove unused prop & behavior that was non-compliant for aria role usage (Advik Kabra)
  * Maintenance: Set up an `wagtail.models.AbstractWorkflow` model to support future customisations around workflows (Hossein)
+ * Maintenance: Improve `classnames` template tag to handle nested lists of strings (LB (Ben) Johnston)
 
 
 6.0 (07.02.2024)
diff --git a/docs/releases/6.1.md b/docs/releases/6.1.md
index 2e72da2547..e5cbe4176e 100644
--- a/docs/releases/6.1.md
+++ b/docs/releases/6.1.md
@@ -41,6 +41,7 @@ depth: 1
  * Adjust Eslint rules for TypeScript files (Karthik Ayangar)
  * Rename the React `Button` that only renders links (a element) to `Link` and remove unused prop & behavior that was non-compliant for aria role usage (Advik Kabra)
  * Set up an `wagtail.models.AbstractWorkflow` model to support future customisations around workflows (Hossein)
+ * Improve `classnames` template tag to handle nested lists of strings (LB (Ben) Johnston)
 
 
 ## Upgrade considerations