diff --git a/Dockerfile b/Dockerfile
index 30f3ba7..5e5b517 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM php:7.4-cli as base
+FROM php:8.1-cli as base
 RUN apt-get update && apt-get install -y libzip4
 
 FROM base as build_extensions
@@ -7,12 +7,12 @@ RUN apt-get update && apt-get install -y libzip-dev \
     && docker-php-ext-install gettext zip \
     && docker-php-ext-enable gettext zip
 
-FROM composer:2.0.13 as staging
+FROM composer:2 as staging
 
 RUN apk --no-cache add git
 
 WORKDIR /composer-require-checker
-ARG revision=3.2.0
+ARG revision=4.5.0
 ENV COMPOSER_REQUIRE_CHECKER_VERSION=${revision}
 RUN git clone https://github.com/maglnet/ComposerRequireChecker.git /composer-require-checker
 RUN git checkout $revision \
diff --git a/README.md b/README.md
index fd8f798..8cb12d5 100644
--- a/README.md
+++ b/README.md
@@ -15,9 +15,9 @@ jobs:
     name: ComposerRequireChecker
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: ComposerRequireChecker
-      uses: docker://webfactory/composer-require-checker:3.2.0
+      uses: docker://webfactory/composer-require-checker:4.5.0
 ```
 
 This configuration will use the pre-built image at the Docker Hub. If you
@@ -33,17 +33,17 @@ jobs:
     name: ComposerRequireChecker
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: ComposerRequireChecker
--      uses: docker://webfactory/composer-require-checker:3.2.0
-+      uses: webfactory/docker-composer-require-checker@0.2.0
+-      uses: docker://webfactory/composer-require-checker:4.5.0
++      uses: webfactory/docker-composer-require-checker@0.3.0
 ```
 
 *Note:* When using the Docker image, the tag refers to the Docker image tag.
 When referring to this repo, use a tag or commit hash for the Dockerfile.
 
 *Note:* This will build the Docker image every time your workflow is run.
-The build will currently use the `3.2.0` release tag of `ComposerRequireChecker`,
+The build will currently use the `4.5.0` release tag of `ComposerRequireChecker`,
 which is the latest version as of writing.
 
 In either case, to pass a custom config file, add this:
@@ -57,9 +57,9 @@ jobs:
     name: ComposerRequireChecker
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v3
     - name: ComposerRequireChecker
-      uses: docker://webfactory/composer-require-checker:3.2.0
+      uses: docker://webfactory/composer-require-checker:4.5.0
 +      with:
 +        args: --config-file=composer-require-checker.js
 ```
@@ -69,7 +69,7 @@ jobs:
 Apart from GitHub Actions, you can run the Docker image in any given
 directory:
 
-`docker run --rm -it -v ${PWD}:/app webfactory/composer-require-checker:3.2.0`
+`docker run --rm -it -v ${PWD}:/app webfactory/composer-require-checker:4.5.0`
 
 ## Credits, Copyright and License
 
@@ -80,4 +80,4 @@ developer looking for new challenges, we'd like to hear from you!
 - <https://www.webfactory.de>
 - <https://twitter.com/webfactory>
 
-Copyright 2019 – 2021 webfactory GmbH, Bonn. Code released under [the MIT license](LICENSE).
+Copyright 2019 – 2023 webfactory GmbH, Bonn. Code released under [the MIT license](LICENSE).