diff --git a/CHANGELOG.md b/CHANGELOG.md
index 807da06d..3ffc512e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,15 @@
 
 All notable changes to this project will be documented in this file. See [standard-version](https://github.com/conventional-changelog/standard-version) for commit guidelines.
 
+## [21.0.0](https://github.com/cybozu/eslint-config/compare/v20.0.1...v21.0.0) (2023-07-19)
+
+
+### ⚠ BREAKING CHANGES
+
+* Drop Prettier v2 support
+
+* update prettier and eslint-config-prettier ([#687](https://github.com/cybozu/eslint-config/issues/687)) ([de15262](https://github.com/cybozu/eslint-config/commit/de15262aba1c4162ca2aeac4f452bab4939cc31f))
+
 ### [20.0.1](https://github.com/cybozu/eslint-config/compare/v19.0.0...v20.0.1) (2023-06-16)
 
 
diff --git a/package-lock.json b/package-lock.json
index 1abfcd37..adff8140 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "@cybozu/eslint-config",
-  "version": "20.0.1",
+  "version": "21.0.0",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@cybozu/eslint-config",
-      "version": "20.0.1",
+      "version": "21.0.0",
       "license": "MIT",
       "dependencies": {
         "@typescript-eslint/eslint-plugin": "^5.59.11",
diff --git a/package.json b/package.json
index 754c3963..67135a8f 100644
--- a/package.json
+++ b/package.json
@@ -6,7 +6,7 @@
   "repository": "cybozu/eslint-config",
   "homepage": "https://github.com/cybozu/eslint-config",
   "bugs": "https://github.com/cybozu/eslint-config/issues",
-  "version": "20.0.1",
+  "version": "21.0.0",
   "description": "ESLint rules for Cybozu",
   "main": "index.js",
   "files": [