diff --git a/tests/Driver/NullDriverTest.php b/tests/Driver/NullDriverTest.php
index a740fc3..f85e53f 100644
--- a/tests/Driver/NullDriverTest.php
+++ b/tests/Driver/NullDriverTest.php
@@ -10,6 +10,8 @@
 
 final class NullDriverTest extends TestCase
 {
+    private NullDriver $queue;
+
     protected function setUp(): void
     {
         parent::setUp();
diff --git a/tests/QueueManagerTest.php b/tests/QueueManagerTest.php
index 2714880..869e432 100644
--- a/tests/QueueManagerTest.php
+++ b/tests/QueueManagerTest.php
@@ -16,6 +16,7 @@
 final class QueueManagerTest extends TestCase
 {
     private m\MockInterface|FactoryInterface $factory;
+    private QueueManager $manager;
 
     protected function setUp(): void
     {