diff --git a/tests/Doctrine/Tests/ORM/EntityManagerTest.php b/tests/Doctrine/Tests/ORM/EntityManagerTest.php
index 37a444a60..a412bb309 100644
--- a/tests/Doctrine/Tests/ORM/EntityManagerTest.php
+++ b/tests/Doctrine/Tests/ORM/EntityManagerTest.php
@@ -2,6 +2,15 @@
 
 namespace Doctrine\Tests\ORM;
 
+use Doctrine\DBAL\Logging\DebugStack;
+use Doctrine\DBAL\Logging\SQLLogger;
+use Doctrine\ORM\Configuration;
+use Doctrine\ORM\EntityManager;
+use Doctrine\ORM\Tools\SchemaTool;
+use Doctrine\ORM\Tools\ToolsException;
+use Doctrine\Tests\Models\Generic\DateTimeModel;
+use Doctrine\Tests\TestUtil;
+
 class EntityManagerTest extends \Doctrine\Tests\OrmTestCase
 {
     private $_em;
@@ -195,4 +204,187 @@ class EntityManagerTest extends \Doctrine\Tests\OrmTestCase
         $this->assertSame($this->_em, $em);
         return 'callback';
     }
+
+    public function testMergeDetachedUnInitializedProxy()
+    {
+        $em = $this->createEntityManager();
+
+        $detachedUninitialized = $em->getReference(DateTimeModel::CLASSNAME, 123);
+
+        $em->clear();
+
+        $managed = $em->getReference(DateTimeModel::CLASSNAME, 123);
+
+        $this->assertSame($managed, $em->merge($detachedUninitialized));
+
+        $this->assertFalse($managed->__isInitialized());
+        $this->assertFalse($detachedUninitialized->__isInitialized());
+    }
+
+    public function testMergeUnserializedUnInitializedProxy()
+    {
+        $em = $this->createEntityManager();
+
+        $detachedUninitialized = $em->getReference(DateTimeModel::CLASSNAME, 123);
+
+        $em->clear();
+
+        $managed = $em->getReference(DateTimeModel::CLASSNAME, 123);
+
+        $this->assertSame(
+            $managed,
+            $em->merge(unserialize(serialize($em->merge($detachedUninitialized))))
+        );
+
+        $this->assertFalse($managed->__isInitialized());
+        $this->assertFalse($detachedUninitialized->__isInitialized());
+    }
+
+    public function testMergeManagedProxy()
+    {
+        $em = $this->createEntityManager();
+
+        $managed = $em->getReference(DateTimeModel::CLASSNAME, 123);
+
+        $this->assertSame($managed, $em->merge($managed));
+
+        $this->assertFalse($managed->__isInitialized());
+    }
+
+    public function testMergingProxyFromDifferentEntityManagerWithExistingManagedInstanceDoesNotReplaceInitializer()
+    {
+        $em1 = $this->createEntityManager($logger1 = new DebugStack());
+        $em2 = $this->createEntityManager($logger2 = new DebugStack());
+
+        $entity1 = new DateTimeModel();
+        $entity2 = new DateTimeModel();
+
+        $em1->persist($entity1);
+        $em2->persist($entity2);
+        $em1->flush();
+        $em2->flush();
+        $em1->clear();
+        $em2->clear();
+
+        $queryCount1 = count($logger1->queries);
+        $queryCount2 = count($logger2->queries);
+
+        $proxy1  = $em1->getReference(DateTimeModel::CLASSNAME, $entity1->id);
+        $proxy2  = $em2->getReference(DateTimeModel::CLASSNAME, $entity1->id);
+        $merged2 = $em2->merge($proxy1);
+
+        $this->assertNotSame($proxy1, $merged2);
+        $this->assertSame($proxy2, $merged2);
+
+        $this->assertFalse($proxy1->__isInitialized());
+        $this->assertFalse($proxy2->__isInitialized());
+
+        $proxy1->__load();
+
+        $this->assertCount(
+            $queryCount1 + 1,
+            $logger1->queries,
+            'Loading the first proxy was done through the first entity manager'
+        );
+        $this->assertCount(
+            $queryCount2,
+            $logger2->queries,
+            'No queries were executed on the second entity manager, as it is unrelated with the first proxy'
+        );
+
+        $proxy2->__load();
+
+        $this->assertCount(
+            $queryCount1 + 1,
+            $logger1->queries,
+            'Loading the second proxy does not affect the first entity manager'
+        );
+        $this->assertCount(
+            $queryCount2 + 1,
+            $logger2->queries,
+            'Loading of the second proxy instance was done through the second entity manager'
+        );
+    }
+
+    public function testMergingUnInitializedProxyDoesNotInitializeIt()
+    {
+        $em1 = $this->createEntityManager($logger1 = new DebugStack());
+        $em2 = $this->createEntityManager($logger2 = new DebugStack());
+
+        $entity1 = new DateTimeModel();
+        $entity2 = new DateTimeModel();
+
+        $em1->persist($entity1);
+        $em2->persist($entity2);
+        $em1->flush();
+        $em2->flush();
+        $em1->clear();
+        $em2->clear();
+
+        $queryCount1 = count($logger1->queries);
+        $queryCount2 = count($logger1->queries);
+
+        $unManagedProxy = $em1->getReference(DateTimeModel::CLASSNAME, $entity1->id);
+        $mergedInstance = $em2->merge($unManagedProxy);
+
+        $this->assertNotInstanceOf('Doctrine\Common\Proxy\Proxy', $mergedInstance);
+        $this->assertNotSame($unManagedProxy, $mergedInstance);
+        $this->assertFalse($unManagedProxy->__isInitialized());
+
+        $this->assertCount(
+            $queryCount1,
+            $logger1->queries,
+            'Loading the merged instance affected only the first entity manager'
+        );
+        $this->assertCount(
+            $queryCount1 + 1,
+            $logger2->queries,
+            'Loading the merged instance was done via the second entity manager'
+        );
+
+        $unManagedProxy->__load();
+
+        $this->assertCount(
+            $queryCount1 + 1,
+            $logger1->queries,
+            'Loading the first proxy was done through the first entity manager'
+        );
+        $this->assertCount(
+            $queryCount2 + 1,
+            $logger2->queries,
+            'No queries were executed on the second entity manager, as it is unrelated with the first proxy'
+        );
+    }
+
+    /**
+     * @param SQLLogger $logger
+     *
+     * @return \Doctrine\ORM\EntityManager
+     */
+    private function createEntityManager(SQLLogger $logger = null)
+    {
+        $config = new Configuration();
+
+        $config->setProxyDir(realpath(__DIR__ . '/../Proxies/../..'));
+        $config->setProxyNamespace('Doctrine\Tests\Proxies');
+        $config->setMetadataDriverImpl($config->newDefaultAnnotationDriver(
+            array(realpath(__DIR__ . '/../Models/Cache')),
+            true
+        ));
+
+        $connection = TestUtil::getConnection();
+
+        $connection->getConfiguration()->setSQLLogger($logger);
+
+        $entityManager = EntityManager::create($connection, $config);
+
+        try {
+            (new SchemaTool($entityManager))
+                ->createSchema([$entityManager->getClassMetadata(DateTimeModel::CLASSNAME)]);
+        } catch (ToolsException $ignored) {
+            // tables were already created
+        }
+
+        return $entityManager;
+    }
 }