diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3ad3759..506848f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,4 @@
-# next
+# 4.0.0 (November 14, 2019)
 
 * Update CSSO to [^4.0.0](https://github.com/css/csso/releases/tag/v4.0.0)
 * Plugin never produce a parse error, but drops bad parts of CSS instead
diff --git a/package-lock.json b/package-lock.json
index 95bee98..5d96fed 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "gulp-csso",
-  "version": "3.0.1",
+  "version": "4.0.0",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
diff --git a/package.json b/package.json
index b11882b..d2a66e4 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "gulp-csso",
-  "version": "3.0.1",
+  "version": "4.0.0",
   "description": "Minify CSS with CSSO.",
   "license": "MIT",
   "files": [