diff --git a/CHANGELOG.md b/CHANGELOG.md
index 050b8bd..ca0ddde 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 ## [Unreleased]
 
+## v4.0.0 - 2024-09-09
+
 > [!IMPORTANT]
 > The new slide container styles, `block` container and safe centering, produce breaking changes to existing slide layouts. ([#382](https://github.com/marp-team/marp-core/pull/382))
 >
diff --git a/package-lock.json b/package-lock.json
index 22aa737..2f3cb16 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@marp-team/marp-core",
-  "version": "3.9.0",
+  "version": "4.0.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "@marp-team/marp-core",
-      "version": "3.9.0",
+      "version": "4.0.0",
       "license": "MIT",
       "dependencies": {
         "@marp-team/marpit": "^3.1.1",
diff --git a/package.json b/package.json
index 08ac90a..c6ae69b 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@marp-team/marp-core",
-  "version": "3.9.0",
+  "version": "4.0.0",
   "description": "The core of Marp tools",
   "license": "MIT",
   "author": {