diff --git a/src/Symfony/Component/Security/Acl/Domain/ObjectIdentity.php b/src/Symfony/Component/Security/Acl/Domain/ObjectIdentity.php
index 2bd152a606..e37e82b0e1 100644
--- a/src/Symfony/Component/Security/Acl/Domain/ObjectIdentity.php
+++ b/src/Symfony/Component/Security/Acl/Domain/ObjectIdentity.php
@@ -11,6 +11,7 @@
 
 namespace Symfony\Component\Security\Acl\Domain;
 
+use Symfony\Component\Security\Core\Util\ClassUtils;
 use Symfony\Component\Security\Acl\Exception\InvalidDomainObjectException;
 use Symfony\Component\Security\Acl\Model\DomainObjectInterface;
 use Symfony\Component\Security\Acl\Model\ObjectIdentityInterface;
@@ -59,9 +60,9 @@ final class ObjectIdentity implements ObjectIdentityInterface
 
         try {
             if ($domainObject instanceof DomainObjectInterface) {
-                return new self($domainObject->getObjectIdentifier(), get_class($domainObject));
+                return new self($domainObject->getObjectIdentifier(), ClassUtils::getRealClass($domainObject));
             } elseif (method_exists($domainObject, 'getId')) {
-                return new self($domainObject->getId(), get_class($domainObject));
+                return new self($domainObject->getId(), ClassUtils::getRealClass($domainObject));
             }
         } catch (\InvalidArgumentException $invalid) {
             throw new InvalidDomainObjectException($invalid->getMessage(), 0, $invalid);
diff --git a/src/Symfony/Component/Security/Acl/Domain/UserSecurityIdentity.php b/src/Symfony/Component/Security/Acl/Domain/UserSecurityIdentity.php
index df2be3850e..6bc1ba18b4 100644
--- a/src/Symfony/Component/Security/Acl/Domain/UserSecurityIdentity.php
+++ b/src/Symfony/Component/Security/Acl/Domain/UserSecurityIdentity.php
@@ -13,6 +13,7 @@ namespace Symfony\Component\Security\Acl\Domain;
 
 use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
 use Symfony\Component\Security\Core\User\UserInterface;
+use Symfony\Component\Security\Core\Util\ClassUtils;
 use Symfony\Component\Security\Acl\Model\SecurityIdentityInterface;
 
 /**
@@ -52,7 +53,7 @@ final class UserSecurityIdentity implements SecurityIdentityInterface
      */
     static public function fromAccount(UserInterface $user)
     {
-        return new self($user->getUsername(), get_class($user));
+        return new self($user->getUsername(), ClassUtils::getRealClass($user));
     }
 
     /**
@@ -69,7 +70,7 @@ final class UserSecurityIdentity implements SecurityIdentityInterface
             return self::fromAccount($user);
         }
 
-        return new self((string) $user, is_object($user)? get_class($user) : get_class($token));
+        return new self((string) $user, is_object($user) ? ClassUtils::getRealClass($user) : ClassUtils::getRealClass($token));
     }
 
     /**
diff --git a/src/Symfony/Component/Security/Core/Util/ClassUtils.php b/src/Symfony/Component/Security/Core/Util/ClassUtils.php
new file mode 100644
index 0000000000..7b583a328c
--- /dev/null
+++ b/src/Symfony/Component/Security/Core/Util/ClassUtils.php
@@ -0,0 +1,55 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Symfony\Component\Security\Core\Util;
+
+/**
+ * Class related functionality for objects that
+ * might or might not be proxy objects at the moment.
+ *
+ * @see Doctrine\Common\Util\ClassUtils
+ *
+ * @author Benjamin Eberlei <kontakt@beberlei.de>
+ * @author Johannes Schmitt <schmittjoh@gmail.com>
+ */
+class ClassUtils
+{
+    /**
+     * Marker for Proxy class names.
+     *
+     * @var string
+     */
+    const MARKER = '__CG__';
+
+    /**
+     * Length of the proxy marker
+     *
+     * @var int
+     */
+    const MARKER_LENGTH = 6;
+
+    /**
+     * Gets the real class name of a class name that could be a proxy.
+     *
+     * @param string|object
+     * @return string
+     */
+    public static function getRealClass($object)
+    {
+        $class = is_object($object) ? get_class($object) : $object;
+
+        if (false === $pos = strrpos($class, '\\'.self::MARKER.'\\')) {
+            return $class;
+        }
+
+        return substr($class, $pos + self::MARKER_LENGTH + 2);
+    }
+}
diff --git a/src/Symfony/Component/Security/Tests/Acl/Domain/ObjectIdentityTest.php b/src/Symfony/Component/Security/Tests/Acl/Domain/ObjectIdentityTest.php
index 20dbedfdf5..20c74d5eeb 100644
--- a/src/Symfony/Component/Security/Tests/Acl/Domain/ObjectIdentityTest.php
+++ b/src/Symfony/Component/Security/Tests/Acl/Domain/ObjectIdentityTest.php
@@ -9,83 +9,108 @@
  * file that was distributed with this source code.
  */
 
-namespace Symfony\Component\Security\Tests\Acl\Domain;
-
-use Symfony\Component\Security\Acl\Domain\ObjectIdentity;
-
-class ObjectIdentityTest extends \PHPUnit_Framework_TestCase
+namespace Symfony\Component\Security\Tests\Acl\Domain
 {
-    public function testConstructor()
+    use Symfony\Component\Security\Acl\Domain\ObjectIdentity;
+    
+    class ObjectIdentityTest extends \PHPUnit_Framework_TestCase
     {
-        $id = new ObjectIdentity('fooid', 'footype');
+        public function testConstructor()
+        {
+            $id = new ObjectIdentity('fooid', 'footype');
+    
+            $this->assertEquals('fooid', $id->getIdentifier());
+            $this->assertEquals('footype', $id->getType());
+        }
 
-        $this->assertEquals('fooid', $id->getIdentifier());
-        $this->assertEquals('footype', $id->getType());
-    }
+        // Test that constructor never changes passed type, even with proxies
+        public function testConstructorWithProxy()
+        {
+            $id = new ObjectIdentity('fooid', 'Acme\DemoBundle\Proxy\__CG__\Symfony\Component\Security\Tests\Acl\Domain\TestDomainObject');
 
-    public function testFromDomainObjectPrefersInterfaceOverGetId()
-    {
-        $domainObject = $this->getMock('Symfony\Component\Security\Acl\Model\DomainObjectInterface');
-        $domainObject
-            ->expects($this->once())
-            ->method('getObjectIdentifier')
-            ->will($this->returnValue('getObjectIdentifier()'))
-        ;
-        $domainObject
-            ->expects($this->never())
-            ->method('getId')
-            ->will($this->returnValue('getId()'))
-        ;
+            $this->assertEquals('fooid', $id->getIdentifier());
+            $this->assertEquals('Acme\DemoBundle\Proxy\__CG__\Symfony\Component\Security\Tests\Acl\Domain\TestDomainObject', $id->getType());
+        }
+    
+        public function testFromDomainObjectPrefersInterfaceOverGetId()
+        {
+            $domainObject = $this->getMock('Symfony\Component\Security\Acl\Model\DomainObjectInterface');
+            $domainObject
+                ->expects($this->once())
+                ->method('getObjectIdentifier')
+                ->will($this->returnValue('getObjectIdentifier()'))
+            ;
+            $domainObject
+                ->expects($this->never())
+                ->method('getId')
+                ->will($this->returnValue('getId()'))
+            ;
+    
+            $id = ObjectIdentity::fromDomainObject($domainObject);
+            $this->assertEquals('getObjectIdentifier()', $id->getIdentifier());
+        }
+    
+        public function testFromDomainObjectWithoutInterface()
+        {
+            $id = ObjectIdentity::fromDomainObject(new TestDomainObject());
+            $this->assertEquals('getId()', $id->getIdentifier());
+            $this->assertEquals('Symfony\Component\Security\Tests\Acl\Domain\TestDomainObject', $id->getType());
+        }
 
-        $id = ObjectIdentity::fromDomainObject($domainObject);
-        $this->assertEquals('getObjectIdentifier()', $id->getIdentifier());
-    }
-
-    public function testFromDomainObjectWithoutInterface()
-    {
-        $id = ObjectIdentity::fromDomainObject(new TestDomainObject());
-        $this->assertEquals('getId()', $id->getIdentifier());
-    }
-
-    /**
-     * @dataProvider getCompareData
-     */
-    public function testEquals($oid1, $oid2, $equal)
-    {
-        if ($equal) {
-            $this->assertTrue($oid1->equals($oid2));
-        } else {
-            $this->assertFalse($oid1->equals($oid2));
+        public function testFromDomainObjectWithProxy()
+        {
+            $id = ObjectIdentity::fromDomainObject(new \Acme\DemoBundle\Proxy\__CG__\Symfony\Component\Security\Tests\Acl\Domain\TestDomainObject());
+            $this->assertEquals('getId()', $id->getIdentifier());
+            $this->assertEquals('Symfony\Component\Security\Tests\Acl\Domain\TestDomainObject', $id->getType());
+        }
+    
+        /**
+         * @dataProvider getCompareData
+         */
+        public function testEquals($oid1, $oid2, $equal)
+        {
+            if ($equal) {
+                $this->assertTrue($oid1->equals($oid2));
+            } else {
+                $this->assertFalse($oid1->equals($oid2));
+            }
+        }
+    
+        public function getCompareData()
+        {
+            return array(
+                array(new ObjectIdentity('123', 'foo'), new ObjectIdentity('123', 'foo'), true),
+                array(new ObjectIdentity('123', 'foo'), new ObjectIdentity(123, 'foo'), true),
+                array(new ObjectIdentity('1', 'foo'), new ObjectIdentity('2', 'foo'), false),
+                array(new ObjectIdentity('1', 'bla'), new ObjectIdentity('1', 'blub'), false),
+            );
+        }
+    
+        protected function setUp()
+        {
+            if (!class_exists('Doctrine\DBAL\DriverManager')) {
+                $this->markTestSkipped('The Doctrine2 DBAL is required for this test');
+            }
         }
     }
-
-    public function getCompareData()
+    
+    class TestDomainObject
     {
-        return array(
-            array(new ObjectIdentity('123', 'foo'), new ObjectIdentity('123', 'foo'), true),
-            array(new ObjectIdentity('123', 'foo'), new ObjectIdentity(123, 'foo'), true),
-            array(new ObjectIdentity('1', 'foo'), new ObjectIdentity('2', 'foo'), false),
-            array(new ObjectIdentity('1', 'bla'), new ObjectIdentity('1', 'blub'), false),
-        );
-    }
-
-    protected function setUp()
-    {
-        if (!class_exists('Doctrine\DBAL\DriverManager')) {
-            $this->markTestSkipped('The Doctrine2 DBAL is required for this test');
+        public function getObjectIdentifier()
+        {
+            return 'getObjectIdentifier()';
+        }
+    
+        public function getId()
+        {
+            return 'getId()';
         }
     }
 }
 
-class TestDomainObject
+namespace Acme\DemoBundle\Proxy\__CG__\Symfony\Component\Security\Tests\Acl\Domain
 {
-    public function getObjectIdentifier()
+    class TestDomainObject extends \Symfony\Component\Security\Tests\Acl\Domain\TestDomainObject
     {
-        return 'getObjectIdentifier()';
-    }
-
-    public function getId()
-    {
-        return 'getId()';
     }
 }
diff --git a/src/Symfony/Component/Security/Tests/Acl/Domain/UserSecurityIdentityTest.php b/src/Symfony/Component/Security/Tests/Acl/Domain/UserSecurityIdentityTest.php
index bb98fd0989..9650803ee2 100644
--- a/src/Symfony/Component/Security/Tests/Acl/Domain/UserSecurityIdentityTest.php
+++ b/src/Symfony/Component/Security/Tests/Acl/Domain/UserSecurityIdentityTest.php
@@ -24,6 +24,15 @@ class UserSecurityIdentityTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('Foo', $id->getClass());
     }
 
+    // Test that constructor never changes the type, even for proxies
+    public function testContructorWithProxy()
+    {
+        $id = new UserSecurityIdentity('foo', 'Acme\DemoBundle\Proxy\__CG__\Symfony\Component\Security\Tests\Acl\Domain\Foo');
+
+        $this->assertEquals('foo', $id->getUsername());
+        $this->assertEquals('Acme\DemoBundle\Proxy\__CG__\Symfony\Component\Security\Tests\Acl\Domain\Foo', $id->getClass());
+    }
+
     /**
      * @dataProvider getCompareData
      */
diff --git a/src/Symfony/Component/Security/Tests/Core/Util/ClassUtilsTest.php b/src/Symfony/Component/Security/Tests/Core/Util/ClassUtilsTest.php
new file mode 100644
index 0000000000..7a6e698754
--- /dev/null
+++ b/src/Symfony/Component/Security/Tests/Core/Util/ClassUtilsTest.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace Symfony\Component\Security\Tests\Core\Util
+{
+    use Symfony\Component\Security\Core\Util\ClassUtils;
+    
+    class ClassUtilsTest extends \PHPUnit_Framework_TestCase
+    {
+        static public function dataGetClass()
+        {
+            return array(
+                array('stdClass', 'stdClass'),
+                array('Symfony\Component\Security\Core\Util\ClassUtils', 'Symfony\Component\Security\Core\Util\ClassUtils'),
+                array('MyProject\Proxies\__CG__\stdClass', 'stdClass'),
+                array('MyProject\Proxies\__CG__\OtherProject\Proxies\__CG__\stdClass', 'stdClass'),
+                array('MyProject\Proxies\__CG__\Symfony\Component\Security\Tests\Core\Util\ChildObject', 'Symfony\Component\Security\Tests\Core\Util\ChildObject'),
+                array(new TestObject(), 'Symfony\Component\Security\Tests\Core\Util\TestObject'),
+                array(new \Acme\DemoBundle\Proxy\__CG__\Symfony\Component\Security\Tests\Core\Util\TestObject(), 'Symfony\Component\Security\Tests\Core\Util\TestObject'),
+            );
+        }
+    
+        /**
+         * @dataProvider dataGetClass
+         */
+        public function testGetRealClass($object, $expectedClassName)
+        {
+            $this->assertEquals($expectedClassName, ClassUtils::getRealClass($object));
+        }
+    }
+
+    class TestObject
+    {
+    }
+}
+
+namespace Acme\DemoBundle\Proxy\__CG__\Symfony\Component\Security\Tests\Core\Util
+{
+    class TestObject extends \Symfony\Component\Security\Tests\Core\Util\TestObject
+    {
+    }
+}