diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 909d37f2..21bdbe40 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,10 +6,12 @@ on:
 
 jobs:
   PHPUnit:
-    runs-on: ubuntu-20.04
+    name: PHPUnit (PHP ${{ matrix.php }})
+    runs-on: ubuntu-22.04
     strategy:
       matrix:
         php:
+          - 8.2
           - 8.1
           - 8.0
           - 7.4
@@ -22,10 +24,11 @@ jobs:
           - 5.4
           - 5.3
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ matrix.php }}
+          coverage: xdebug
       - run: composer install
       - run: vendor/bin/phpunit --coverage-text
         if: ${{ matrix.php >= 7.3 }}
@@ -34,11 +37,16 @@ jobs:
 
   PHPUnit-hhvm:
     name: PHPUnit (HHVM)
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-22.04
+    continue-on-error: true
     steps:
-      - uses: actions/checkout@v2
-      - uses: azjezz/setup-hhvm@v1
+      - uses: actions/checkout@v3
+      - run: cp "$(which composer)" composer.phar && ./composer.phar self-update --2.2 # downgrade Composer for HHVM
+      - name: Run hhvm composer.phar install
+        uses: docker://hhvm/hhvm:3.30-lts-latest
         with:
-          version: lts-3.30
-      - run: hhvm $(which composer) install
-      - run: hhvm vendor/bin/phpunit
+          args: hhvm composer.phar install
+      - name: Run hhvm vendor/bin/phpunit
+        uses: docker://hhvm/hhvm:3.30-lts-latest
+        with:
+          args: hhvm vendor/bin/phpunit
diff --git a/README.md b/README.md
index b6621525..f09d783b 100644
--- a/README.md
+++ b/README.md
@@ -1,12 +1,9 @@
 # graphp/graph
 
-[![CI status](https://github.com/graphp/graph/actions/workflows/ci.yml/badge.svg?branch=v0.9.x)](https://github.com/graphp/graph/actions)
+[![CI status](https://github.com/graphp/graph/actions/workflows/ci.yml/badge.svg?branch=0.9.x)](https://github.com/graphp/graph/actions)
 
 GraPHP is the mathematical graph/network library written in PHP.
 
->   You're viewing the contents of the `v0.9.x` release branch, note that active
-    development continues on another branch, see `master` branch for more details.
-
 **Table of contents**
 
 * [Quickstart examples](#quickstart-examples)
@@ -109,7 +106,7 @@ The recommended way to install this library is [through Composer](https://getcom
 This will install the latest supported version:
 
 ```bash
-$ composer require clue/graph:^0.9.3
+composer require clue/graph:^0.9.3
 ```
 
 See also the [CHANGELOG](CHANGELOG.md) for details about version upgrades.
@@ -129,13 +126,13 @@ To run the test suite, you first need to clone this repo and then install all
 dependencies [through Composer](https://getcomposer.org/):
 
 ```bash
-$ composer install
+composer install
 ```
 
 To run the test suite, go to the project root and run:
 
 ```bash
-$ vendor/bin/phpunit
+vendor/bin/phpunit
 ```
 
 ## Contributing
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index fffc7f59..e462441b 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -17,4 +17,7 @@
             <directory>./src/</directory>
         </include>
     </coverage>
+    <php>
+        <ini name="error_reporting" value="-1" />
+    </php>
 </phpunit>
diff --git a/tests/VertexTest.php b/tests/VertexTest.php
index 73880225..6575a06a 100644
--- a/tests/VertexTest.php
+++ b/tests/VertexTest.php
@@ -8,6 +8,12 @@
 
 class VertexTest extends AbstractAttributeAwareTest
 {
+    /** @var Graph */
+    private $graph;
+
+    /** @var Vertex */
+    private $vertex;
+
     /**
      * @before
      */