diff --git a/.github/workflows/fix-cs-php.yml b/.github/workflows/fix-cs-php.yml
index 3fbfe58..8d9f924 100644
--- a/.github/workflows/fix-cs-php.yml
+++ b/.github/workflows/fix-cs-php.yml
@@ -21,7 +21,7 @@ jobs:
                     ref: ${{ github.head_ref }}
 
             -   name: Run PHP-CS-Fixer
-                uses: docker://oskarstark/php-cs-fixer-ga:3.11.0
+                uses: docker://ghcr.io/webfactory/php-cs-fixer:3.62.0
 
             -   name: Commit and push back changes
                 uses: stefanzweifel/git-auto-commit-action@v4
diff --git a/src/Build/TreeFactory.php b/src/Build/TreeFactory.php
index d2bb660..bbaa1e5 100644
--- a/src/Build/TreeFactory.php
+++ b/src/Build/TreeFactory.php
@@ -52,9 +52,9 @@ public function __construct(
         ConfigCacheFactoryInterface $configCacheFactory,
         $cacheFile,
         ContainerInterface $container,
-        EventDispatcherInterface $eventDispatcher = null,
-        LoggerInterface $logger = null,
-        Stopwatch $stopwatch = null
+        ?EventDispatcherInterface $eventDispatcher = null,
+        ?LoggerInterface $logger = null,
+        ?Stopwatch $stopwatch = null
     ) {
         $this->configCacheFactory = $configCacheFactory;
         $this->cacheFile = $cacheFile;
@@ -80,7 +80,7 @@ protected function startTiming(string $sectionName): ?StopwatchEvent
         return null;
     }
 
-    protected function stopTiming(StopwatchEvent $watch = null): void
+    protected function stopTiming(?StopwatchEvent $watch = null): void
     {
         if ($watch) {
             $watch->stop();
diff --git a/src/Tree/Node.php b/src/Tree/Node.php
index ee2cc48..11d13f4 100644
--- a/src/Tree/Node.php
+++ b/src/Tree/Node.php
@@ -18,7 +18,7 @@ class Node implements \ArrayAccess
     /**
      * @var Node|null
      */
-    protected $parent = null;
+    protected $parent;
 
     protected $data = ['visible' => false, 'breadcrumbsVisible' => true, 'url' => false, 'caption' => ''];
 
@@ -34,7 +34,7 @@ class Node implements \ArrayAccess
      *
      * @return Node returns the given or newly created node, for use in fluent notations
      */
-    public function addChild(self $n = null): self
+    public function addChild(?self $n = null): self
     {
         if (null === $n) {
             $n = new self();
@@ -243,17 +243,12 @@ public function isActivePath(): bool
         return $this === $ap || $this->hasDescendant($ap);
     }
 
-    /**
-     * @param mixed $offset
-     */
     public function offsetExists($offset): bool
     {
         return isset($this->data[$offset]);
     }
 
     /**
-     * @param mixed $offset
-     *
      * @return mixed|null
      */
     #[\ReturnTypeWillChange]
@@ -262,18 +257,11 @@ public function offsetGet($offset)
         return $this->get($offset);
     }
 
-    /**
-     * @param mixed $offset
-     * @param mixed $value
-     */
     public function offsetSet($offset, $value): void
     {
         $this->set($offset, $value);
     }
 
-    /**
-     * @param mixed $offset
-     */
     public function offsetUnset($offset): void
     {
         unset($this->data[$offset]);
diff --git a/src/Tree/Tree.php b/src/Tree/Tree.php
index 22d65d0..115550a 100644
--- a/src/Tree/Tree.php
+++ b/src/Tree/Tree.php
@@ -19,7 +19,7 @@ class Tree
      *
      * @var Node|null
      */
-    protected $activeNode = null;
+    protected $activeNode;
 
     /**
      * The "closest to active" node in this tree.
@@ -30,14 +30,14 @@ class Tree
      *
      * @var ?Node
      */
-    protected $activePath = null;
+    protected $activePath;
 
     public function __construct()
     {
         $this->finder = new Finder();
     }
 
-    public function addRoot(Node $r = null): Node
+    public function addRoot(?Node $r = null): Node
     {
         if (null === $r) {
             $r = new Node();
diff --git a/src/Twig/NavigationExtension.php b/src/Twig/NavigationExtension.php
index 5e4644b..693b76d 100644
--- a/src/Twig/NavigationExtension.php
+++ b/src/Twig/NavigationExtension.php
@@ -177,7 +177,7 @@ public function getPowerSet(array $baseSet): array
         $members = 2 ** $count;
         $powerSet = [];
         for ($i = 0; $i < $members; ++$i) {
-            $b = sprintf('%0'.$count.'b', $i);
+            $b = \sprintf('%0'.$count.'b', $i);
             $out = [];
             for ($j = 0; $j < $count; ++$j) {
                 if ('1' == $b[$j]) {