diff --git a/tests/Adapter/Doctrine/DoctrineFactoryTest.php b/tests/Adapter/Doctrine/DoctrineFactoryTest.php
index 5bef1c3..7acdead 100644
--- a/tests/Adapter/Doctrine/DoctrineFactoryTest.php
+++ b/tests/Adapter/Doctrine/DoctrineFactoryTest.php
@@ -15,6 +15,7 @@
 
 use Doctrine\ORM\EntityManager;
 use Doctrine\Persistence\ManagerRegistry;
+use Doctrine\Persistence\ObjectManager;
 use Mezcalito\UxSearchBundle\Adapter\Doctrine\DoctrineAdapter;
 use Mezcalito\UxSearchBundle\Adapter\Doctrine\DoctrineFactory;
 use Mezcalito\UxSearchBundle\Exception\DoctrineAdapterException;
@@ -63,7 +64,7 @@ public function testCreateAdapterThrowsLogicExceptionWhenManagerRegistryIsNull()
 
     public function testCreateAdapterThrowsDoctrineAdapterExceptionForInvalidManager(): void
     {
-        $invalidManager = new \stdClass();
+        $invalidManager = $this->createMock(ObjectManager::class);
         $managerRegistryMock = $this->createMock(ManagerRegistry::class);
         $managerRegistryMock->expects($this->once())
             ->method('getManager')