diff --git a/Registry.php b/Registry.php
index 0b943e4d3..19034aca6 100644
--- a/Registry.php
+++ b/Registry.php
@@ -3,9 +3,11 @@
 namespace Doctrine\Bundle\DoctrineBundle;
 
 use Doctrine\ORM\ORMException;
+use ProxyManager\Proxy\LazyLoadingInterface;
 use Psr\Container\ContainerInterface;
 use Symfony\Bridge\Doctrine\ManagerRegistry;
 use Symfony\Contracts\Service\ResetInterface;
+use function interface_exists;
 
 /**
  * References all Doctrine connections and entity managers in a given Container.
@@ -50,6 +52,10 @@ public function getAliasNamespace($alias)
 
     public function reset() : void
     {
+        if (! interface_exists(LazyLoadingInterface::class)) {
+            return;
+        }
+
         foreach (array_keys($this->getManagerNames()) as $managerName) {
             $this->resetManager($managerName);
         }
diff --git a/Tests/RegistryTest.php b/Tests/RegistryTest.php
index 89ebb7dda..a2eccabcd 100644
--- a/Tests/RegistryTest.php
+++ b/Tests/RegistryTest.php
@@ -123,17 +123,13 @@ public function testResetUnknownEntityManager()
         $registry->resetManager('default');
     }
 
-    /**
-     * @group legacy
-     */
     public function testReset()
     {
-        $em        = new stdClass();
         $container = $this->getMockBuilder('Symfony\Component\DependencyInjection\ContainerInterface')->getMock();
         $container->expects($this->once())
-            ->method('get')
+            ->method('initialized')
             ->with($this->equalTo('doctrine.orm.default_entity_manager'))
-            ->will($this->returnValue($em));
+            ->will($this->returnValue(false));
 
         $registry = new Registry($container, [], ['default' => 'doctrine.orm.default_entity_manager'], 'default', 'default');
         $registry->reset();
diff --git a/composer.json b/composer.json
index 88d593ce9..bed6ef9d8 100644
--- a/composer.json
+++ b/composer.json
@@ -40,6 +40,7 @@
     "require-dev": {
         "doctrine/coding-standard": "^6.0",
         "doctrine/orm": "^2.6",
+        "ocramius/proxy-manager": "^2.1",
         "phpunit/phpunit": "^7.5",
         "symfony/phpunit-bridge": "^4.2",
         "symfony/property-info": "^4.3.3|^5.0",