diff --git a/CHANGELOG.md b/CHANGELOG.md
index 16bc374..08eb584 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## Unreleased
 
+## 2.4.0 (2026-09-09)
+
 - feat: Add `Checker:option`, which returns the value the schema resolves an option to. An extension no longer decides for itself what counts as true, so `enabled: no` means the same thing in every extension.
 - feat: Add `Checker:attributes`, which checks one element's attributes against the `attributes` section and returns what they resolve to. Both the element's own group and `_any` apply, the named group last.
 - docs: State that `Checker:options` reads the metadata of its first call only. A later call returns what the first call resolved, so a caller that needs a second document checked builds a second checker.
diff --git a/CITATION.cff b/CITATION.cff
index c4592ab..827036d 100644
--- a/CITATION.cff
+++ b/CITATION.cff
@@ -8,5 +8,5 @@ authors:
     orcid: "https://orcid.org/0000-0002-3396-4549"
 repository-code: "https://github.com/mcanouil/quarto-lua-modules"
 license: MIT
-date-released: "2026-09-07"
-version: 2.3.0
+date-released: "2026-09-09"
+version: 2.4.0