diff --git a/lib/Doctrine/ORM/AbstractQuery.php b/lib/Doctrine/ORM/AbstractQuery.php
index 07af294b1..333107c73 100644
--- a/lib/Doctrine/ORM/AbstractQuery.php
+++ b/lib/Doctrine/ORM/AbstractQuery.php
@@ -22,7 +22,7 @@ namespace Doctrine\ORM;
 use Doctrine\DBAL\Types\Type,
     Doctrine\DBAL\Cache\QueryCacheProfile,
     Doctrine\ORM\Query\QueryException,
-    Doctrine\ORM\Internal\Hydration\CacheHydrator;
+    Doctrine\Common\Util\ClassUtils;
 
 /**
  * Base contract for ORM queries. Base class for Query and NativeQuery.
@@ -241,7 +241,7 @@ abstract class AbstractQuery
 
                 return $value;
 
-            case is_object($value) && $this->_em->getMetadataFactory()->hasMetadataFor(get_class($value)):
+            case is_object($value) && $this->_em->getMetadataFactory()->hasMetadataFor(ClassUtils::getClass($value)):
                 return $this->convertObjectParameterToScalarValue($value);
 
             default:
diff --git a/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php b/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
index 63ac01c25..befc2973c 100644
--- a/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
+++ b/lib/Doctrine/ORM/Mapping/ClassMetadataFactory.php
@@ -24,6 +24,7 @@ use ReflectionException,
     Doctrine\ORM\EntityManager,
     Doctrine\DBAL\Platforms,
     Doctrine\ORM\Events,
+    Doctrine\Common\Util\ClassUtils,
     Doctrine\Common\Persistence\Mapping\RuntimeReflectionService,
     Doctrine\Common\Persistence\Mapping\ReflectionService,
     Doctrine\Common\Persistence\Mapping\ClassMetadataFactory as ClassMetadataFactoryInterface;
@@ -154,41 +155,44 @@ class ClassMetadataFactory implements ClassMetadataFactoryInterface
      */
     public function getMetadataFor($className)
     {
-        if ( ! isset($this->loadedMetadata[$className])) {
-            $realClassName = $className;
+        if (isset($this->loadedMetadata[$className])) {
+            return $this->loadedMetadata[$className];
+        }
 
-            // Check for namespace alias
-            if (strpos($className, ':') !== false) {
-                list($namespaceAlias, $simpleClassName) = explode(':', $className);
-                $realClassName = $this->em->getConfiguration()->getEntityNamespace($namespaceAlias) . '\\' . $simpleClassName;
+        $realClassName = $className;
 
-                if (isset($this->loadedMetadata[$realClassName])) {
-                    // We do not have the alias name in the map, include it
-                    $this->loadedMetadata[$className] = $this->loadedMetadata[$realClassName];
+        // Check for namespace alias
+        if (strpos($className, ':') !== false) {
+            list($namespaceAlias, $simpleClassName) = explode(':', $className);
+            $realClassName = $this->em->getConfiguration()->getEntityNamespace($namespaceAlias) . '\\' . $simpleClassName;
+        } else {
+            $realClassName = ClassUtils::getRealClass($realClassName);
+        }
 
-                    return $this->loadedMetadata[$realClassName];
-                }
-            }
+        if (isset($this->loadedMetadata[$realClassName])) {
+            // We do not have the alias name in the map, include it
+            $this->loadedMetadata[$className] = $this->loadedMetadata[$realClassName];
+            return $this->loadedMetadata[$realClassName];
+        }
 
-            if ($this->cacheDriver) {
-                if (($cached = $this->cacheDriver->fetch("$realClassName\$CLASSMETADATA")) !== false) {
-                    $this->wakeupReflection($cached, $this->getReflectionService());
-                    $this->loadedMetadata[$realClassName] = $cached;
-                } else {
-                    foreach ($this->loadMetadata($realClassName) as $loadedClassName) {
-                        $this->cacheDriver->save(
-                            "$loadedClassName\$CLASSMETADATA", $this->loadedMetadata[$loadedClassName], null
-                        );
-                    }
-                }
+        if ($this->cacheDriver) {
+            if (($cached = $this->cacheDriver->fetch("$realClassName\$CLASSMETADATA")) !== false) {
+                $this->wakeupReflection($cached, $this->getReflectionService());
+                $this->loadedMetadata[$realClassName] = $cached;
             } else {
-                $this->loadMetadata($realClassName);
+                foreach ($this->loadMetadata($realClassName) as $loadedClassName) {
+                    $this->cacheDriver->save(
+                        "$loadedClassName\$CLASSMETADATA", $this->loadedMetadata[$loadedClassName], null
+                    );
+                }
             }
+        } else {
+            $this->loadMetadata($realClassName);
+        }
 
-            if ($className != $realClassName) {
-                // We do not have the alias name in the map, include it
-                $this->loadedMetadata[$className] = $this->loadedMetadata[$realClassName];
-            }
+        if ($className != $realClassName) {
+            // We do not have the alias name in the map, include it
+            $this->loadedMetadata[$className] = $this->loadedMetadata[$realClassName];
         }
 
         return $this->loadedMetadata[$className];
diff --git a/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php b/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php
index d2638bea5..48508981d 100644
--- a/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php
+++ b/lib/Doctrine/ORM/Persisters/BasicEntityPersister.php
@@ -32,7 +32,8 @@ use PDO,
     Doctrine\ORM\Mapping\MappingException,
     Doctrine\ORM\Mapping\ClassMetadata,
     Doctrine\ORM\Events,
-    Doctrine\ORM\Event\LifecycleEventArgs;
+    Doctrine\ORM\Event\LifecycleEventArgs,
+    Doctrine\Common\Util\ClassUtils;
 
 /**
  * A BasicEntityPersiter maps an entity to a single table in a relational database.
@@ -1499,7 +1500,7 @@ class BasicEntityPersister
      */
     private function getIndividualValue($value)
     {
-        if (is_object($value) && $this->_em->getMetadataFactory()->hasMetadataFor(get_class($value))) {
+        if (is_object($value) && $this->_em->getMetadataFactory()->hasMetadataFor(ClassUtils::getClass($value))) {
             if ($this->_em->getUnitOfWork()->getEntityState($value) === UnitOfWork::STATE_MANAGED) {
                 $idValues = $this->_em->getUnitOfWork()->getEntityIdentifier($value);
             } else {
diff --git a/lib/Doctrine/ORM/Proxy/ProxyFactory.php b/lib/Doctrine/ORM/Proxy/ProxyFactory.php
index 21d033e7e..df10798e1 100644
--- a/lib/Doctrine/ORM/Proxy/ProxyFactory.php
+++ b/lib/Doctrine/ORM/Proxy/ProxyFactory.php
@@ -93,10 +93,6 @@ class ProxyFactory
             require $fileName;
         }
 
-        if ( ! $this->_em->getMetadataFactory()->hasMetadataFor($fqn)) {
-            $this->_em->getMetadataFactory()->setMetadataFor($fqn, $this->_em->getClassMetadata($className));
-        }
-
         $entityPersister = $this->_em->getUnitOfWork()->getEntityPersister($className);
 
         return new $fqn($entityPersister, $identifier);
diff --git a/lib/Doctrine/ORM/UnitOfWork.php b/lib/Doctrine/ORM/UnitOfWork.php
index 410f3b2c6..c1244934b 100644
--- a/lib/Doctrine/ORM/UnitOfWork.php
+++ b/lib/Doctrine/ORM/UnitOfWork.php
@@ -886,7 +886,7 @@ class UnitOfWork implements PropertyChangedListener
         $hasListeners          = $this->evm->hasListeners(Events::postPersist);
 
         foreach ($this->entityInsertions as $oid => $entity) {
-            if (get_class($entity) !== $className) {
+            if ($this->em->getClassMetadata(get_class($entity))->name !== $className) {
                 continue;
             }
 
@@ -945,7 +945,7 @@ class UnitOfWork implements PropertyChangedListener
         $hasPostUpdateListeners          = $this->evm->hasListeners(Events::postUpdate);
 
         foreach ($this->entityUpdates as $oid => $entity) {
-            if ( ! (get_class($entity) === $className || $entity instanceof Proxy && get_parent_class($entity) === $className)) {
+            if ($this->em->getClassMetadata(get_class($entity))->name !== $className) {
                 continue;
             }
 
@@ -992,7 +992,7 @@ class UnitOfWork implements PropertyChangedListener
         $hasListeners = $this->evm->hasListeners(Events::postRemove);
 
         foreach ($this->entityDeletions as $oid => $entity) {
-            if ( ! (get_class($entity) == $className || $entity instanceof Proxy && get_parent_class($entity) == $className)) {
+            if ($this->em->getClassMetadata(get_class($entity))->name !== $className) {
                 continue;
             }
 
@@ -1043,7 +1043,7 @@ class UnitOfWork implements PropertyChangedListener
         $newNodes = array();
 
         foreach ($entityChangeSet as $entity) {
-            $className = get_class($entity);
+            $className = $this->em->getClassMetadata(get_class($entity))->name;
 
             if ($calc->hasClass($className)) {
                 continue;
@@ -1357,7 +1357,7 @@ class UnitOfWork implements PropertyChangedListener
                 }
 
                 // db lookup
-                if ($this->getEntityPersister(get_class($entity))->exists($entity)) {
+                if ($this->getEntityPersister($class->name)->exists($entity)) {
                     return self::STATE_DETACHED;
                 }
 
@@ -1374,7 +1374,7 @@ class UnitOfWork implements PropertyChangedListener
                 }
 
                 // db lookup
-                if ($this->getEntityPersister(get_class($entity))->exists($entity)) {
+                if ($this->getEntityPersister($class->name)->exists($entity)) {
                     return self::STATE_DETACHED;
                 }
 
@@ -2151,13 +2151,12 @@ class UnitOfWork implements PropertyChangedListener
             throw ORMInvalidArgumentException::entityNotManaged($entity);
         }
 
-        $entityName = get_class($entity);
-        $class = $this->em->getClassMetadata($entityName);
+        $class = $this->em->getClassMetadata(get_class($entity));
 
         switch ($lockMode) {
             case \Doctrine\DBAL\LockMode::OPTIMISTIC;
                 if ( ! $class->isVersioned) {
-                    throw OptimisticLockException::notVersioned($entityName);
+                    throw OptimisticLockException::notVersioned($class->name);
                 }
 
                 if ($lockVersion === null) {
diff --git a/tests/Doctrine/Tests/ORM/Functional/ProxiesLikeEntitiesTest.php b/tests/Doctrine/Tests/ORM/Functional/ProxiesLikeEntitiesTest.php
new file mode 100644
index 000000000..52ac8f591
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/Functional/ProxiesLikeEntitiesTest.php
@@ -0,0 +1,133 @@
+<?php
+
+namespace Doctrine\Tests\ORM\Functional;
+
+use Doctrine\Common\Util\ClassUtils,
+    Doctrine\Tests\Models\CMS\CmsUser,
+    Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser as Proxy;
+
+/**
+ * Test that Doctrine ORM correctly works with proxy instances exactly like with ordinary Entities
+ *
+ * The test considers two possible cases:
+ *  a) __initialized__ = true and no identifier set in proxy
+ *  b) __initialized__ = false and identifier set in proxy and in property
+ * @todo All other cases would cause lazy loading issues
+ */
+class ProxiesLikeEntitiesTest extends \Doctrine\Tests\OrmFunctionalTestCase
+{
+    /**
+     * @var CmsUser
+     */
+    protected $user;
+
+    protected function setUp()
+    {
+        parent::setUp();
+        try {
+            $this->_schemaTool->createSchema(array(
+                $this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser'),
+            ));
+        } catch (\Exception $e) {
+        }
+        $this->user = new CmsUser();
+        $this->user->username = 'ocramius';
+        $this->user->name = 'Marco';
+        $this->_em->persist($this->user);
+        $this->_em->flush();
+        $this->_em->clear();
+    }
+
+    /**
+     * Verifies that a proxy can be successfully persisted and updated
+     */
+    public function testPersistUpdate()
+    {
+        // Considering case (a)
+        $persister = $this->_em->getUnitOfWork()->getEntityPersister('Doctrine\Tests\Models\CMS\CmsUser');
+        $proxy = new Proxy($persister, array());
+        $proxy->__isInitialized__ = true;
+        $proxy->username = 'ocra';
+        $proxy->name = 'Marco';
+        $this->_em->persist($proxy);
+        $this->_em->flush();
+        $this->assertNotNull($proxy->getId());
+        $proxy->name = 'Marco Pivetta';
+        $this
+            ->_em
+            ->getUnitOfWork()
+            ->computeChangeSet($this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser'), $proxy);
+        $this->assertNotEmpty($this->_em->getUnitOfWork()->getEntityChangeSet($proxy));
+        $this->assertEquals('Marco Pivetta', $this->_em->find('Doctrine\Tests\Models\CMS\CmsUser', $proxy->getId())->name);
+        $this->_em->remove($proxy);
+        $this->_em->flush();
+    }
+
+    public function testEntityWithIdentifier()
+    {
+        // Considering case (b)
+        $persister = $this->_em->getUnitOfWork()->getEntityPersister('Doctrine\Tests\Models\CMS\CmsUser');
+        $uninitializedProxy = new Proxy($persister, array('id' => $this->user->getId()));
+        $uninitializedProxy->id = $this->user->getId();
+        $uninitializedProxy->username = 'ocra';
+        $uninitializedProxy->name = 'Marco Pivetta';
+        $this->_em->persist($uninitializedProxy);
+        $this->_em->flush();
+        $this->assertEquals($this->user->getId(), $uninitializedProxy->getId());
+        $this->_em->remove($uninitializedProxy);
+        $this->_em->flush();
+    }
+
+    /**
+     * Verifying that proxies can be used without problems as query parameters
+     */
+    public function testProxyAsDqlParameterPersist()
+    {
+        $persister = $this->_em->getUnitOfWork()->getEntityPersister('Doctrine\Tests\Models\CMS\CmsUser');
+        $proxy = new Proxy($persister, array('id' => $this->user->getId()));
+        $proxy->id = $this->user->getId();
+        $result = $this
+            ->_em
+            ->createQuery('SELECT u FROM Doctrine\Tests\Models\CMS\CmsUser u WHERE u = ?1')
+            ->setParameter(1, $proxy)
+            ->getSingleResult();
+        $this->assertSame($this->user->getId(), $result->getId());
+        $this->_em->remove($proxy);
+        $this->_em->flush();
+    }
+
+    /**
+     * Verifying that proxies can be used without problems as query parameters
+     */
+    public function testFindWithProxyName()
+    {
+        $result = $this
+            ->_em
+            ->find('Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser', $this->user->getId());
+        $this->assertSame($this->user->getId(), $result->getId());
+        $this->_em->clear();
+        $result = $this
+            ->_em
+            ->getReference('Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser', $this->user->getId());
+        $this->assertSame($this->user->getId(), $result->getId());
+        $this->_em->clear();
+        $result = $this
+            ->_em
+            ->getRepository('Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser')
+            ->findOneBy(array('username' => $this->user->username));
+        $this->assertSame($this->user->getId(), $result->getId());
+        $this->_em->clear();
+        $result = $this
+            ->_em
+            ->createQuery('SELECT u FROM Doctrine\Tests\Proxies\__CG__\Doctrine\Tests\Models\CMS\CmsUser u WHERE u.id = ?1')
+            ->setParameter(1, $this->user->getId())
+            ->getSingleResult();
+        $this->assertSame($this->user->getId(), $result->getId());
+        $this->_em->clear();
+    }
+
+    protected function tearDown()
+    {
+        $this->_em->createQuery('DELETE FROM Doctrine\Tests\Models\CMS\CmsUser u')->execute();
+    }
+}
\ No newline at end of file