diff --git a/Tests/Fixtures/DummyManager.php b/Tests/Fixtures/DummyManager.php
new file mode 100644
index 00000000..04e5a2ac
--- /dev/null
+++ b/Tests/Fixtures/DummyManager.php
@@ -0,0 +1,69 @@
+<?php
+
+namespace Symfony\Bridge\Doctrine\Tests\Fixtures;
+
+use Doctrine\Persistence\Mapping\ClassMetadata;
+use Doctrine\Persistence\Mapping\ClassMetadataFactory;
+use Doctrine\Persistence\ObjectManager;
+use Doctrine\Persistence\ObjectRepository;
+
+class DummyManager implements ObjectManager
+{
+    public $bar;
+
+    public function find($className, $id): ?object
+    {
+    }
+
+    public function persist($object): void
+    {
+    }
+
+    public function remove($object): void
+    {
+    }
+
+    public function merge($object)
+    {
+    }
+
+    public function clear($objectName = null): void
+    {
+    }
+
+    public function detach($object): void
+    {
+    }
+
+    public function refresh($object): void
+    {
+    }
+
+    public function flush(): void
+    {
+    }
+
+    public function getRepository($className): ObjectRepository
+    {
+    }
+
+    public function getClassMetadata($className): ClassMetadata
+    {
+    }
+
+    public function getMetadataFactory(): ClassMetadataFactory
+    {
+    }
+
+    public function initializeObject($obj): void
+    {
+    }
+
+    public function contains($object): bool
+    {
+    }
+
+    public function isUninitializedObject($value): bool
+    {
+    }
+}
diff --git a/Tests/ManagerRegistryTest.php b/Tests/ManagerRegistryTest.php
index 1b32453d..fa44ba0a 100644
--- a/Tests/ManagerRegistryTest.php
+++ b/Tests/ManagerRegistryTest.php
@@ -11,7 +11,9 @@
 
 namespace Symfony\Bridge\Doctrine\Tests;
 
+use Doctrine\Persistence\ObjectManager;
 use PHPUnit\Framework\TestCase;
+use Symfony\Bridge\Doctrine\Tests\Fixtures\DummyManager;
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
@@ -24,8 +26,8 @@ public static function setUpBeforeClass(): void
     {
         $container = new ContainerBuilder();
 
-        $container->register('foo', \stdClass::class)->setPublic(true);
-        $container->getDefinition('foo')->setLazy(true)->addTag('proxy', ['interface' => \stdClass::class]);
+        $container->register('foo', DummyManager::class)->setPublic(true);
+        $container->getDefinition('foo')->setLazy(true)->addTag('proxy', ['interface' => ObjectManager::class]);
         $container->compile();
 
         $dumper = new PhpDumper($container);
@@ -46,8 +48,8 @@ public function testResetService()
         $registry->resetManager();
 
         $this->assertSame($foo, $container->get('foo'));
-        $this->assertInstanceOf(\stdClass::class, $foo);
-        $this->assertFalse(property_exists($foo, 'bar'));
+        $this->assertInstanceOf(ObjectManager::class, $foo);
+        $this->assertFalse(isset($foo->bar));
     }
 
     /**
@@ -79,7 +81,7 @@ public function testResetServiceWillNotNestFurtherLazyServicesWithinEachOther()
 
         $service = $container->get('foo');
 
-        self::assertInstanceOf(\stdClass::class, $service);
+        self::assertInstanceOf(ObjectManager::class, $service);
         self::assertInstanceOf(LazyObjectInterface::class, $service);
         self::assertFalse($service->isLazyObjectInitialized());
 
@@ -92,7 +94,7 @@ public function testResetServiceWillNotNestFurtherLazyServicesWithinEachOther()
         $service->initializeLazyObject();
 
         $wrappedValue = $service->initializeLazyObject();
-        self::assertInstanceOf(\stdClass::class, $wrappedValue);
+        self::assertInstanceOf(DummyManager::class, $wrappedValue);
         self::assertNotInstanceOf(LazyObjectInterface::class, $wrappedValue);
     }
 
@@ -104,10 +106,10 @@ private function dumpLazyServiceDoctrineBridgeContainerAsFiles()
 
         $container = new ContainerBuilder();
 
-        $container->register('foo', \stdClass::class)
+        $container->register('foo', DummyManager::class)
             ->setPublic(true)
             ->setLazy(true)
-            ->addTag('proxy', ['interface' => \stdClass::class]);
+            ->addTag('proxy', ['interface' => ObjectManager::class]);
         $container->compile();
 
         $fileSystem = new Filesystem();