diff --git a/src/Theme/ThemeManager.php b/src/Theme/ThemeManager.php
index 815ffb91be..900212f020 100644
--- a/src/Theme/ThemeManager.php
+++ b/src/Theme/ThemeManager.php
@@ -116,9 +116,6 @@ class ThemeManager
         $this->activeTheme = $theme;
         $this->theme = $this->themes[$theme];
 
-        // need to set later
-        //$this->setThemeCookie();
-
         return true;
     }
 
@@ -230,7 +227,14 @@ class ThemeManager
         return array_key_exists($theme ?? '', $this->themes);
     }
 
-    /** @return mixed[] */
+    /** @return array{
+     *   id: string,
+     *   name: string,
+     *   version: string,
+     *   is_active: bool,
+     *   color_mode: string,
+     *   color_modes: array<string|int, string>
+     * }[] $themes */
     public function getThemesArray(): array
     {
         $themes = [];
diff --git a/tests/unit/Theme/ThemeManagerTest.php b/tests/unit/Theme/ThemeManagerTest.php
index fd175ca220..8f79d9c7f7 100644
--- a/tests/unit/Theme/ThemeManagerTest.php
+++ b/tests/unit/Theme/ThemeManagerTest.php
@@ -54,11 +54,6 @@ class ThemeManagerTest extends AbstractTestCase
         $tm->initializeTheme();
         $themes = $tm->getThemesArray();
         self::assertArrayHasKey(0, $themes);
-        self::assertIsArray($themes[0]);
-        self::assertArrayHasKey('id', $themes[0]);
-        self::assertArrayHasKey('name', $themes[0]);
-        self::assertArrayHasKey('version', $themes[0]);
-        self::assertArrayHasKey('is_active', $themes[0]);
     }
 
     /**