diff --git a/typo3/sysext/core/Classes/Imaging/Dimension.php b/typo3/sysext/core/Classes/Imaging/Dimension.php
index 65f0125a466b..26ffc6303cde 100644
--- a/typo3/sysext/core/Classes/Imaging/Dimension.php
+++ b/typo3/sysext/core/Classes/Imaging/Dimension.php
@@ -40,6 +40,9 @@ class Dimension
     public function __construct($size = Icon::SIZE_MEDIUM)
     {
         switch ($size) {
+            case Icon::SIZE_MEGA:
+                $sizeInPixel = 64;
+                break;
             case Icon::SIZE_LARGE:
                 $sizeInPixel = 48;
                 break;
diff --git a/typo3/sysext/core/Classes/Imaging/Icon.php b/typo3/sysext/core/Classes/Imaging/Icon.php
index 22b5d2a2f7e1..66675d38ef4d 100644
--- a/typo3/sysext/core/Classes/Imaging/Icon.php
+++ b/typo3/sysext/core/Classes/Imaging/Icon.php
@@ -46,6 +46,11 @@ class Icon
      */
     public const SIZE_LARGE = 'large'; // 48px
 
+    /**
+     * @var string the mega size
+     */
+    public const SIZE_MEGA = 'mega'; // 64px
+
     /**
      * @internal
      * @var string the overlay size, which depends on icon size
diff --git a/typo3/sysext/core/Tests/Unit/Imaging/IconTest.php b/typo3/sysext/core/Tests/Unit/Imaging/IconTest.php
index eed3427dc906..a04ed13ba5e8 100644
--- a/typo3/sysext/core/Tests/Unit/Imaging/IconTest.php
+++ b/typo3/sysext/core/Tests/Unit/Imaging/IconTest.php
@@ -80,4 +80,47 @@ public function getStateReturnsCorrectIdentifier(): void
     {
         self::assertTrue($this->subject->getState()->equals(IconState::STATE_DISABLED));
     }
+
+    public static function setSizeSetsExpectedValuesDataProvider(): \Generator
+    {
+        yield 'SIZE_DEFAULT' => [
+            Icon::SIZE_DEFAULT,
+            [16, 16],
+        ];
+        yield 'SIZE_SMALL' => [
+            Icon::SIZE_DEFAULT,
+            [16, 16],
+        ];
+        yield 'SIZE_OVERLAY' => [
+            Icon::SIZE_OVERLAY,
+            [16, 16],
+        ];
+        yield 'SIZE_MEDIUM' => [
+            Icon::SIZE_MEDIUM,
+            [32, 32],
+        ];
+        yield 'SIZE_LARGE' => [
+            Icon::SIZE_LARGE,
+            [48, 48],
+        ];
+        yield 'SIZE_MEGA' => [
+            Icon::SIZE_MEGA,
+            [64, 64],
+        ];
+    }
+
+    /**
+     * @test
+     * @dataProvider setSizeSetsExpectedValuesDataProvider
+     */
+    public function setSizeSetsExpectedValues(string $size, array $expectedDimensions): void
+    {
+        $icon = new Icon();
+        $icon->setSize($size);
+
+        [$width, $height] = $expectedDimensions;
+
+        self::assertSame($width, $icon->getDimension()->getWidth());
+        self::assertSame($height, $icon->getDimension()->getHeight());
+    }
 }