diff --git a/typo3/sysext/seo/Classes/Canonical/CanonicalGenerator.php b/typo3/sysext/seo/Classes/Canonical/CanonicalGenerator.php
index 9ce7216871fcbe32e25f36b84287951ba29c6548..4088b3f0392178ab3d0b27491fd05582a067ac9a 100644
--- a/typo3/sysext/seo/Classes/Canonical/CanonicalGenerator.php
+++ b/typo3/sysext/seo/Classes/Canonical/CanonicalGenerator.php
@@ -47,7 +47,7 @@ class CanonicalGenerator
      */
     protected $eventDispatcher;
 
-    public function __construct(TypoScriptFrontendController $typoScriptFrontendController = null, EventDispatcherInterface $eventDispatcher = null)
+    public function __construct(?TypoScriptFrontendController $typoScriptFrontendController = null, ?EventDispatcherInterface $eventDispatcher = null)
     {
         $this->eventDispatcher = $eventDispatcher ?? GeneralUtility::makeInstance(EventDispatcherInterface::class);
         $this->typoScriptFrontendController = $typoScriptFrontendController ?? $this->getTypoScriptFrontendController();
diff --git a/typo3/sysext/seo/Classes/XmlSitemap/AbstractXmlSitemapDataProvider.php b/typo3/sysext/seo/Classes/XmlSitemap/AbstractXmlSitemapDataProvider.php
index 738e12a3467cf313312fc50ae53bba24d37a4165..6f9630a24d75fe518647b34d2aa2ab409450262a 100644
--- a/typo3/sysext/seo/Classes/XmlSitemap/AbstractXmlSitemapDataProvider.php
+++ b/typo3/sysext/seo/Classes/XmlSitemap/AbstractXmlSitemapDataProvider.php
@@ -69,7 +69,7 @@ abstract class AbstractXmlSitemapDataProvider implements XmlSitemapDataProviderI
      * @param array $config
      * @param ContentObjectRenderer $cObj
      */
-    public function __construct(ServerRequestInterface $request, string $key, array $config = [], ContentObjectRenderer $cObj = null)
+    public function __construct(ServerRequestInterface $request, string $key, array $config = [], ?ContentObjectRenderer $cObj = null)
     {
         $this->key = $key;
         $this->config = $config;
diff --git a/typo3/sysext/seo/Classes/XmlSitemap/PagesXmlSitemapDataProvider.php b/typo3/sysext/seo/Classes/XmlSitemap/PagesXmlSitemapDataProvider.php
index 05647bbe2353e310f1def0af1dc9ea4273ea041a..fd296db6fb2c7ba2f24a761fe3dddc6995ea757f 100644
--- a/typo3/sysext/seo/Classes/XmlSitemap/PagesXmlSitemapDataProvider.php
+++ b/typo3/sysext/seo/Classes/XmlSitemap/PagesXmlSitemapDataProvider.php
@@ -32,7 +32,7 @@ use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
  */
 class PagesXmlSitemapDataProvider extends AbstractXmlSitemapDataProvider
 {
-    public function __construct(ServerRequestInterface $request, string $key, array $config = [], ContentObjectRenderer $cObj = null)
+    public function __construct(ServerRequestInterface $request, string $key, array $config = [], ?ContentObjectRenderer $cObj = null)
     {
         parent::__construct($request, $key, $config, $cObj);
 
diff --git a/typo3/sysext/seo/Classes/XmlSitemap/RecordsXmlSitemapDataProvider.php b/typo3/sysext/seo/Classes/XmlSitemap/RecordsXmlSitemapDataProvider.php
index c663f1f5229f526f64f22e0c5bae3c43e9c3f69a..7ecda970e81f8b04b21716c12b77fc9cc37bc064 100644
--- a/typo3/sysext/seo/Classes/XmlSitemap/RecordsXmlSitemapDataProvider.php
+++ b/typo3/sysext/seo/Classes/XmlSitemap/RecordsXmlSitemapDataProvider.php
@@ -40,7 +40,7 @@ class RecordsXmlSitemapDataProvider extends AbstractXmlSitemapDataProvider
      * @param ContentObjectRenderer|null $cObj
      * @throws MissingConfigurationException
      */
-    public function __construct(ServerRequestInterface $request, string $key, array $config = [], ContentObjectRenderer $cObj = null)
+    public function __construct(ServerRequestInterface $request, string $key, array $config = [], ?ContentObjectRenderer $cObj = null)
     {
         parent::__construct($request, $key, $config, $cObj);
 
diff --git a/typo3/sysext/seo/Classes/XmlSitemap/XmlSitemapDataProviderInterface.php b/typo3/sysext/seo/Classes/XmlSitemap/XmlSitemapDataProviderInterface.php
index c64f7b34b3fbe041f9771e66cc7cae5edd57a56e..cde22d6664363eb7212128959fa73e429838af6e 100644
--- a/typo3/sysext/seo/Classes/XmlSitemap/XmlSitemapDataProviderInterface.php
+++ b/typo3/sysext/seo/Classes/XmlSitemap/XmlSitemapDataProviderInterface.php
@@ -25,7 +25,7 @@ use TYPO3\CMS\Frontend\ContentObject\ContentObjectRenderer;
  */
 interface XmlSitemapDataProviderInterface
 {
-    public function __construct(ServerRequestInterface $request, string $name, array $config = [], ContentObjectRenderer $cObj = null);
+    public function __construct(ServerRequestInterface $request, string $name, array $config = [], ?ContentObjectRenderer $cObj = null);
     public function getKey(): string;
     public function getItems(): array;
     public function getLastModified(): int;
diff --git a/typo3/sysext/seo/Classes/XmlSitemap/XmlSitemapRenderer.php b/typo3/sysext/seo/Classes/XmlSitemap/XmlSitemapRenderer.php
index a0da0aeeb0d1702b8424ae00b399bf9a4ea50b5b..240ba7a1ceddfcc1ae75e65ad95e35bc83ca75ed 100644
--- a/typo3/sysext/seo/Classes/XmlSitemap/XmlSitemapRenderer.php
+++ b/typo3/sysext/seo/Classes/XmlSitemap/XmlSitemapRenderer.php
@@ -173,7 +173,7 @@ class XmlSitemapRenderer
      * @param string|null $sitemap
      * @return string
      */
-    protected function getXslFilePath(string $sitemapType = null, string $sitemap = null): string
+    protected function getXslFilePath(?string $sitemapType = null, ?string $sitemap = null): string
     {
         $path = $this->configuration['config']['xslFile'] ?? 'EXT:seo/Resources/Public/CSS/Sitemap.xsl';
         $path = ($sitemapType !== null) ? ($this->configuration['config'][$sitemapType]['sitemaps']['xslFile'] ?? $path) : $path;