diff --git a/CHANGES.rst b/CHANGES.rst
index 2b5fce5b..bf4a7e17 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -2,7 +2,7 @@
  Changes
 =========
 
-4.0.0 (unreleased)
+4.0.0 (2023-12-11)
 ==================
 
 - Packaging: Support for Python 3.12 uses released dependencies.
diff --git a/version.txt b/version.txt
index 9e736c7c..fcdb2e10 100644
--- a/version.txt
+++ b/version.txt
@@ -1 +1 @@
-4.0.0a2.dev0
+4.0.0