diff --git a/typo3/sysext/extensionmanager/Classes/Remote/ExtensionDownloaderRemoteInterface.php b/typo3/sysext/extensionmanager/Classes/Remote/ExtensionDownloaderRemoteInterface.php
index b18678614947ccce8fff6ed603798ff5a893deb3..15898905d9d9eb0d611f0f4fe95a9aaa93c23e87 100644
--- a/typo3/sysext/extensionmanager/Classes/Remote/ExtensionDownloaderRemoteInterface.php
+++ b/typo3/sysext/extensionmanager/Classes/Remote/ExtensionDownloaderRemoteInterface.php
@@ -44,5 +44,5 @@ interface ExtensionDownloaderRemoteInterface
      * @throws DownloadFailedException when a remote file could not be loaded.
      * @throws VerificationFailedException when the remote file could not be unpacked or validated.
      */
-    public function downloadExtension(string $extensionKey, string $version, FileHandlingUtility $fileHandler, string $verificationHash = null, string $pathType = 'Local'): void;
+    public function downloadExtension(string $extensionKey, string $version, FileHandlingUtility $fileHandler, ?string $verificationHash = null, string $pathType = 'Local'): void;
 }
diff --git a/typo3/sysext/extensionmanager/Classes/Remote/TerExtensionRemote.php b/typo3/sysext/extensionmanager/Classes/Remote/TerExtensionRemote.php
index 74daca9cfe1d25aaf02d63c3c0e95594521cd4d0..511c00c66590b33b6c2e31675048d843c6400fbf 100644
--- a/typo3/sysext/extensionmanager/Classes/Remote/TerExtensionRemote.php
+++ b/typo3/sysext/extensionmanager/Classes/Remote/TerExtensionRemote.php
@@ -158,7 +158,7 @@ class TerExtensionRemote implements ExtensionDownloaderRemoteInterface, Listable
      * @throws DownloadFailedException
      * @throws VerificationFailedException
      */
-    public function downloadExtension(string $extensionKey, string $version, FileHandlingUtility $fileHandler, string $verificationHash = null, string $pathType = 'Local'): void
+    public function downloadExtension(string $extensionKey, string $version, FileHandlingUtility $fileHandler, ?string $verificationHash = null, string $pathType = 'Local'): void
     {
         $extensionPath = strtolower($extensionKey);
         $remotePath = $extensionPath[0] . '/' . $extensionPath[1] . '/' . $extensionPath . '_' . $version . '.t3x';
diff --git a/typo3/sysext/extensionmanager/Classes/Report/ExtensionComposerStatus.php b/typo3/sysext/extensionmanager/Classes/Report/ExtensionComposerStatus.php
index 60e0d75caa039c3717c953103d1f15489c1877b8..a76045149d93fe185823f5a8c2da6e73c9a513c0 100644
--- a/typo3/sysext/extensionmanager/Classes/Report/ExtensionComposerStatus.php
+++ b/typo3/sysext/extensionmanager/Classes/Report/ExtensionComposerStatus.php
@@ -48,7 +48,7 @@ class ExtensionComposerStatus implements RequestAwareStatusProviderInterface
         $this->uriBuilder = $uriBuilder;
     }
 
-    public function getStatus(ServerRequestInterface $request = null): array
+    public function getStatus(?ServerRequestInterface $request = null): array
     {
         $status = [];
         $extensionsWithComposerDeficit = $this->composerDeficitDetector->getExtensionsWithComposerDeficit();
diff --git a/typo3/sysext/extensionmanager/Classes/Report/ExtensionStatus.php b/typo3/sysext/extensionmanager/Classes/Report/ExtensionStatus.php
index 3aa25d12782182cf4b6053550d76bc8cd8ee3e6a..ca35fad71f0ae28dc2f48828eb32fbd3a8a4b354 100644
--- a/typo3/sysext/extensionmanager/Classes/Report/ExtensionStatus.php
+++ b/typo3/sysext/extensionmanager/Classes/Report/ExtensionStatus.php
@@ -64,7 +64,7 @@ class ExtensionStatus implements StatusProviderInterface
     /**
      * @param RemoteRegistry|null  $remoteRegistry
      */
-    public function __construct(RemoteRegistry $remoteRegistry = null)
+    public function __construct(?RemoteRegistry $remoteRegistry = null)
     {
         $this->remoteRegistry = $remoteRegistry ?? GeneralUtility::makeInstance(RemoteRegistry::class);
         $this->listUtility = GeneralUtility::makeInstance(ListUtility::class);
diff --git a/typo3/sysext/extensionmanager/Classes/Utility/InstallUtility.php b/typo3/sysext/extensionmanager/Classes/Utility/InstallUtility.php
index 9529bb5d038482006c6819930ab7429b495e1f19..44aadb8a5662ba9158bdb812944026330faf842b 100644
--- a/typo3/sysext/extensionmanager/Classes/Utility/InstallUtility.php
+++ b/typo3/sysext/extensionmanager/Classes/Utility/InstallUtility.php
@@ -539,7 +539,7 @@ class InstallUtility implements SingletonInterface, LoggerAwareInterface
      * @param string $packagePath
      * @param Import|null $import
      */
-    protected function importSiteConfiguration(string $extensionKey, string $packagePath, Import $import = null): void
+    protected function importSiteConfiguration(string $extensionKey, string $packagePath, ?Import $import = null): void
     {
         $importAbsFolder = $packagePath . 'Initialisation/Site';
         $destinationFolder = Environment::getConfigPath() . '/sites';