diff --git a/core/Command/Maintenance/Mimetype/GenerateMimetypeFileBuilder.php b/core/Command/Maintenance/Mimetype/GenerateMimetypeFileBuilder.php
index 873744e6f94..611b880cefd 100644
--- a/core/Command/Maintenance/Mimetype/GenerateMimetypeFileBuilder.php
+++ b/core/Command/Maintenance/Mimetype/GenerateMimetypeFileBuilder.php
@@ -31,7 +31,7 @@ class GenerateMimetypeFileBuilder {
 	/**
 	 * Generate mime type list file
 	 *
-	 * @param array $aliases
+	 * @param array<string,string> $aliases
 	 * @return string
 	 */
 	public function generateFile(array $aliases): string {
diff --git a/lib/private/Files/Type/Detection.php b/lib/private/Files/Type/Detection.php
index 71b8cb986d7..a6944995f4c 100644
--- a/lib/private/Files/Type/Detection.php
+++ b/lib/private/Files/Type/Detection.php
@@ -56,32 +56,19 @@ class Detection implements IMimeTypeDetector {
 	private const CUSTOM_MIMETYPEMAPPING = 'mimetypemapping.json';
 	private const CUSTOM_MIMETYPEALIASES = 'mimetypealiases.json';
 
-	protected $mimetypes = [];
-	protected $secureMimeTypes = [];
-
-	protected $mimetypeIcons = [];
-	/** @var string[] */
-	protected $mimeTypeAlias = [];
-
-	/** @var IURLGenerator */
-	private $urlGenerator;
-
-	private LoggerInterface $logger;
-
-	/** @var string */
-	private $customConfigDir;
-
-	/** @var string */
-	private $defaultConfigDir;
-
-	public function __construct(IURLGenerator $urlGenerator,
-		LoggerInterface $logger,
-		string $customConfigDir,
-		string $defaultConfigDir) {
-		$this->urlGenerator = $urlGenerator;
-		$this->logger = $logger;
-		$this->customConfigDir = $customConfigDir;
-		$this->defaultConfigDir = $defaultConfigDir;
+	protected array $mimetypes = [];
+	protected array $secureMimeTypes = [];
+
+	protected array $mimetypeIcons = [];
+	/** @var array<string,string> */
+	protected array $mimeTypeAlias = [];
+
+	public function __construct(
+		private IURLGenerator $urlGenerator,
+		private LoggerInterface $logger,
+		private string $customConfigDir,
+		private string $defaultConfigDir,
+	) {
 	}
 
 	/**
@@ -151,7 +138,7 @@ class Detection implements IMimeTypeDetector {
 	}
 
 	/**
-	 * @return string[]
+	 * @return array<string,string>
 	 */
 	public function getAllAliases(): array {
 		$this->loadAliases();
diff --git a/lib/public/Files/IMimeTypeDetector.php b/lib/public/Files/IMimeTypeDetector.php
index 9992c153edc..4933975e108 100644
--- a/lib/public/Files/IMimeTypeDetector.php
+++ b/lib/public/Files/IMimeTypeDetector.php
@@ -84,7 +84,7 @@ interface IMimeTypeDetector {
 	public function mimeTypeIcon($mimeType);
 
 	/**
-	 * @return string[]
+	 * @return array<string,string>
 	 * @since 28.0.0
 	 */
 	public function getAllAliases(): array;