diff --git a/CHANGELOG.md b/CHANGELOG.md
index 703eb97..7605d27 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,10 +4,15 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [Unreleased](https://github.com/stefanzweifel/git-auto-commit-action/compare/v3.0.0...HEAD)
+## [Unreleased](https://github.com/stefanzweifel/git-auto-commit-action/compare/v4.0.0...HEAD)
 
 > TBD
 
+## [v4.0.0](https://github.com/stefanzweifel/git-auto-commit-action/compare/v3.0.0...v4.0.0) - 2020-02-24
+
+### Changed
+- Switch Action to use `node12`-environment instead of `docker`. 
+
 ## [v3.0.0](https://github.com/stefanzweifel/git-auto-commit-action/compare/v2.5.0...v3.0.0) - 2020-02-06
 
 ### Added
diff --git a/README.md b/README.md
index c50c5c5..b1fbb9a 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ This Action has been inspired and adapted from the [auto-commit](https://github.
 Add the following step at the end of your job.
 
 ```yaml
-- uses: stefanzweifel/git-auto-commit-action@v3.0.0
+- uses: stefanzweifel/git-auto-commit-action@v4.0.0
   with:
     commit_message: Apply automatic changes
 
@@ -71,7 +71,7 @@ jobs:
     - name: Run php-cs-fixer
       uses: docker://oskarstark/php-cs-fixer-ga
 
-    - uses: stefanzweifel/git-auto-commit-action@v3.0.0
+    - uses: stefanzweifel/git-auto-commit-action@v4.0.0
       with:
         commit_message: Apply php-cs-fixer changes
         branch: ${{ github.head_ref }}
@@ -94,7 +94,7 @@ jobs:
     - name: Run php-cs-fixer
       uses: docker://oskarstark/php-cs-fixer-ga
 
-    - uses: stefanzweifel/git-auto-commit-action@v3.0.0
+    - uses: stefanzweifel/git-auto-commit-action@v4.0.0
       with:
         commit_message: Apply php-cs-fixer changes
 ```
@@ -136,7 +136,7 @@ jobs:
     - name: Run php-cs-fixer
       uses: docker://oskarstark/php-cs-fixer-ga
 
-    - uses: stefanzweifel/git-auto-commit-action@v3.0.0
+    - uses: stefanzweifel/git-auto-commit-action@v4.0.0
       with:
         commit_message: Apply php-cs-fixer changes
 ```