diff --git a/Tests/Unit/Domain/Variants/IdBuilderTest.php b/Tests/Unit/Domain/Variants/IdBuilderTest.php
index 157c642946..845ea629d0 100644
--- a/Tests/Unit/Domain/Variants/IdBuilderTest.php
+++ b/Tests/Unit/Domain/Variants/IdBuilderTest.php
@@ -32,21 +32,6 @@
  */
 class IdBuilderTest extends SetUpUnitTestCase
 {
-    protected string $oldEncryptionKey;
-
-    protected function setUp(): void
-    {
-        $this->oldEncryptionKey = $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'];
-        $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] = 'testkey';
-        parent::setUp();
-    }
-
-    protected function tearDown(): void
-    {
-        $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] = $this->oldEncryptionKey;
-        parent::tearDown();
-    }
-
     /**
      * @test
      */
@@ -54,7 +39,7 @@ public function canBuildVariantId(): void
     {
         $build = new IdBuilder(new NoopEventDispatcher());
         $variantId = $build->buildFromTypeAndUid('pages', 4711, [], $this->createMock(Site::class), new Document());
-        self::assertSame('e99b3552a0451f1a2e7aca4ac06ccaba063393de/pages/4711', $variantId);
+        self::assertSame('c523304ea47711019595d2bb352b623d1db40427/pages/4711', $variantId);
     }
 
     /**
diff --git a/Tests/Unit/SetUpUnitTestCase.php b/Tests/Unit/SetUpUnitTestCase.php
index 068ee87ba0..1cfb0b9926 100644
--- a/Tests/Unit/SetUpUnitTestCase.php
+++ b/Tests/Unit/SetUpUnitTestCase.php
@@ -27,13 +27,25 @@
 abstract class SetUpUnitTestCase extends UnitTestCase
 {
     protected bool $resetSingletonInstances = true;
+    protected ?string $originalEncryptionKey;
 
     protected function setUp(): void
     {
         date_default_timezone_set('Europe/Berlin');
+        $this->originalEncryptionKey = $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] ?? null;
+        $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] = 'solr-tests-secret-encryption-key';
         parent::setUp();
     }
 
+    protected function tearDown(): void
+    {
+        unset($GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey']);
+        if ($this->originalEncryptionKey !== null) {
+            $GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'] = $this->originalEncryptionKey;
+        }
+        parent::tearDown();
+    }
+
     /**
      * Returns the absolute root path to the fixtures.
      *