diff --git a/composer.json b/composer.json
index 7d9492fda716..fd1bd7651328 100644
--- a/composer.json
+++ b/composer.json
@@ -24,7 +24,8 @@
 		"phpunit/phpunit": "^9.1",
 		"predis/predis": "^1.1",
 		"rector/rector": "0.10.21",
-		"squizlabs/php_codesniffer": "^3.3"
+		"squizlabs/php_codesniffer": "^3.3",
+		"symplify/composer-json-manipulator": "^9.3"
 	},
 	"suggest": {
 		"ext-fileinfo": "Improves mime type detection for files"
diff --git a/rector.php b/rector.php
index d32d7210a636..7f4305fd2bdd 100644
--- a/rector.php
+++ b/rector.php
@@ -16,6 +16,7 @@
 use Rector\Core\ValueObject\PhpVersion;
 use Rector\DeadCode\Rector\Concat\RemoveConcatAutocastRector;
 use Rector\DeadCode\Rector\Foreach_\RemoveUnusedForeachKeyRector;
+use Rector\DeadCode\Rector\Property\RemoveUnusedPrivatePropertyRector;
 use Rector\DeadCode\Rector\Switch_\RemoveDuplicatedCaseInSwitchRector;
 use Rector\EarlyReturn\Rector\Foreach_\ChangeNestedForeachIfsToEarlyContinueRector;
 use Rector\EarlyReturn\Rector\If_\ChangeIfElseValueAssignToEarlyReturnRector;
@@ -80,4 +81,5 @@
 	$services->set(RemoveConcatAutocastRector::class);
 	$services->set(ChangeArrayPushToArrayAssignRector::class);
 	$services->set(UnnecessaryTernaryExpressionRector::class);
+	$services->set(RemoveUnusedPrivatePropertyRector::class);
 };
diff --git a/tests/system/Helpers/DateHelperTest.php b/tests/system/Helpers/DateHelperTest.php
index 68e7d99e097b..806d4e8a1fd9 100644
--- a/tests/system/Helpers/DateHelperTest.php
+++ b/tests/system/Helpers/DateHelperTest.php
@@ -6,12 +6,6 @@
 
 final class DateHelperTest extends CIUnitTestCase
 {
-
-	private $name;
-	private $value;
-	private $expire;
-	private $response;
-
 	protected function setUp(): void
 	{
 		parent::setUp();