diff --git a/src/Symfony/Component/DependencyInjection/CHANGELOG.md b/src/Symfony/Component/DependencyInjection/CHANGELOG.md
index 9a41e85705..25e7fc66aa 100644
--- a/src/Symfony/Component/DependencyInjection/CHANGELOG.md
+++ b/src/Symfony/Component/DependencyInjection/CHANGELOG.md
@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+2.5.0
+-----
+
+* added DecoratorServicePass and a way to override a service definition (Definition::setDecoratedService())
+
 2.4.0
 -----
 
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/DecoratorServicePass.php b/src/Symfony/Component/DependencyInjection/Compiler/DecoratorServicePass.php
new file mode 100644
index 0000000000..dea9f030ef
--- /dev/null
+++ b/src/Symfony/Component/DependencyInjection/Compiler/DecoratorServicePass.php
@@ -0,0 +1,54 @@
+<?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\DependencyInjection\Compiler;
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Alias;
+
+/**
+ * Overwrites a service but keeps the overridden one.
+ *
+ * @author Christophe Coevoet <stof@notk.org>
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class DecoratorServicePass implements CompilerPassInterface
+{
+    public function process(ContainerBuilder $container)
+    {
+        foreach ($container->getDefinitions() as $id => $definition) {
+            if (!$decorated = $definition->getDecoratedService()) {
+                continue;
+            }
+            $definition->setDecoratedService(null);
+
+            list ($inner, $renamedId) = $decorated;
+            if (!$renamedId) {
+                $renamedId = $id.'.inner';
+            }
+
+            // we create a new alias/service for the service we are replacing
+            // to be able to reference it in the new one
+            if ($container->hasAlias($inner)) {
+                $alias = $container->getAlias($inner);
+                $public = $alias->isPublic();
+                $container->setAlias($renamedId, new Alias((string) $alias, false));
+            } else {
+                $definition = $container->getDefinition($inner);
+                $public = $definition->isPublic();
+                $definition->setPublic(false);
+                $container->setDefinition($renamedId, $definition);
+            }
+
+            $container->setAlias($inner, new Alias($id, $public));
+        }
+    }
+}
diff --git a/src/Symfony/Component/DependencyInjection/Compiler/PassConfig.php b/src/Symfony/Component/DependencyInjection/Compiler/PassConfig.php
index ac395db22e..bcef41052b 100644
--- a/src/Symfony/Component/DependencyInjection/Compiler/PassConfig.php
+++ b/src/Symfony/Component/DependencyInjection/Compiler/PassConfig.php
@@ -46,6 +46,7 @@ class PassConfig
 
         $this->optimizationPasses = array(
             new ResolveDefinitionTemplatesPass(),
+            new DecoratorServicePass(),
             new ResolveParameterPlaceHoldersPass(),
             new CheckDefinitionValidityPass(),
             new ResolveReferencesToAliasesPass(),
diff --git a/src/Symfony/Component/DependencyInjection/Definition.php b/src/Symfony/Component/DependencyInjection/Definition.php
index 428fee27c3..49d7a7cb3d 100644
--- a/src/Symfony/Component/DependencyInjection/Definition.php
+++ b/src/Symfony/Component/DependencyInjection/Definition.php
@@ -38,6 +38,7 @@ class Definition
     private $abstract = false;
     private $synchronized = false;
     private $lazy = false;
+    private $decoratedService;
 
     protected $arguments;
 
@@ -100,6 +101,41 @@ class Definition
         return $this;
     }
 
+    /**
+     * Sets the service that this service is decorating.
+     *
+     * @param null|string $id        The decorated service id, use null to remove decoration
+     * @param null|string $renamedId The new decorated service id
+     *
+     * @return Definition The current instance
+     *
+     * @throws InvalidArgumentException In case the decorated service id and the new decorated service id are equals.
+     */
+    public function setDecoratedService($id, $renamedId = null)
+    {
+        if ($renamedId && $id == $renamedId) {
+            throw new \InvalidArgumentException(sprintf('The decorated service inner name for "%s" must be different than the service name itself.', $id));
+        }
+
+        if (null === $id) {
+            $this->decoratedService = null;
+        } else {
+            $this->decoratedService = array($id, $renamedId);
+        }
+
+        return $this;
+    }
+
+    /**
+     * Gets the service that decorates this service.
+     *
+     * @return null|array An array composed of the decorated service id and the new id for it, null if no service is decorated
+     */
+    public function getDecoratedService()
+    {
+        return $this->decoratedService;
+    }
+
     /**
      * Gets the factory method.
      *
diff --git a/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php b/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php
index 31bec31b22..ec30b15e7b 100644
--- a/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php
+++ b/src/Symfony/Component/DependencyInjection/Dumper/XmlDumper.php
@@ -138,6 +138,13 @@ class XmlDumper extends Dumper
         if ($definition->isLazy()) {
             $service->setAttribute('lazy', 'true');
         }
+        if (null !== $decorated = $definition->getDecoratedService()) {
+            list ($decorated, $renamedId) = $decorated;
+            $service->setAttribute('decorates', $decorated);
+            if (null !== $renamedId) {
+                $service->setAttribute('decoration-inner-name', $renamedId);
+            }
+        }
 
         foreach ($definition->getTags() as $name => $tags) {
             foreach ($tags as $attributes) {
diff --git a/src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php b/src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php
index b4748545dc..9ea4d16b3c 100644
--- a/src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php
+++ b/src/Symfony/Component/DependencyInjection/Dumper/YamlDumper.php
@@ -139,6 +139,14 @@ class YamlDumper extends Dumper
             $code .= sprintf("        scope: %s\n", $scope);
         }
 
+        if (null !== $decorated = $definition->getDecoratedService()) {
+            list ($decorated, $renamedId) = $decorated;
+            $code .= sprintf("        decorates: %s\n", $decorated);
+            if (null !== $renamedId) {
+                $code .= sprintf("        decoration-inner-name: %s\n", $renamedId);
+            }
+        }
+
         if ($callable = $definition->getConfigurator()) {
             if (is_array($callable)) {
                 if ($callable[0] instanceof Reference) {
diff --git a/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php b/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
index 9b2d46d28e..5d7a5a7fd7 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
@@ -197,6 +197,11 @@ class XmlFileLoader extends FileLoader
             $definition->addTag((string) $tag['name'], $parameters);
         }
 
+        if (isset($service['decorates'])) {
+            $renameId = isset($service['decoration-inner-name']) ? (string) $service['decoration-inner-name'] : null;
+            $definition->setDecoratedService((string) $service['decorates'], $renameId);
+        }
+
         $this->container->setDefinition($id, $definition);
     }
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php b/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
index 5a1f946277..394825f57e 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/YamlFileLoader.php
@@ -234,6 +234,11 @@ class YamlFileLoader extends FileLoader
             }
         }
 
+        if (isset($service['decorates'])) {
+            $renameId = isset($service['decoration-inner-name']) ? $service['decoration-inner-name'] : null;
+            $definition->setDecoratedService($service['decorates'], $renameId);
+        }
+
         $this->container->setDefinition($id, $definition);
     }
 
diff --git a/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd b/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd
index f7b578767b..b3521ce0ce 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd
+++ b/src/Symfony/Component/DependencyInjection/Loader/schema/dic/services/services-1.0.xsd
@@ -94,6 +94,8 @@
     <xsd:attribute name="factory-service" type="xsd:string" />
     <xsd:attribute name="alias" type="xsd:string" />
     <xsd:attribute name="parent" type="xsd:string" />
+    <xsd:attribute name="decorates" type="xsd:string" />
+    <xsd:attribute name="decoration-inner-name" type="xsd:string" />
   </xsd:complexType>
 
   <xsd:complexType name="tag">
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Compiler/DecoratorServicePassTest.php b/src/Symfony/Component/DependencyInjection/Tests/Compiler/DecoratorServicePassTest.php
new file mode 100644
index 0000000000..e17961ac99
--- /dev/null
+++ b/src/Symfony/Component/DependencyInjection/Tests/Compiler/DecoratorServicePassTest.php
@@ -0,0 +1,81 @@
+<?php
+
+namespace Symfony\Component\DependencyInjection\Tests\Compiler;
+
+use Symfony\Component\DependencyInjection\Alias;
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+use Symfony\Component\DependencyInjection\Compiler\DecoratorServicePass;
+
+class DecoratorServicePassTest extends \PHPUnit_Framework_TestCase
+{
+    public function testProcessWithoutAlias()
+    {
+        $container = new ContainerBuilder();
+        $fooDefinition = $container
+            ->register('foo')
+            ->setPublic(false)
+        ;
+        $fooExtendedDefinition = $container
+            ->register('foo.extended')
+            ->setPublic(true)
+            ->setDecoratedService('foo')
+        ;
+        $barDefinition = $container
+            ->register('bar')
+            ->setPublic(true)
+        ;
+        $barExtendedDefinition = $container
+            ->register('bar.extended')
+            ->setPublic(true)
+            ->setDecoratedService('bar', 'bar.yoo')
+        ;
+
+        $this->process($container);
+
+        $this->assertEquals('foo.extended', $container->getAlias('foo'));
+        $this->assertFalse($container->getAlias('foo')->isPublic());
+
+        $this->assertEquals('bar.extended', $container->getAlias('bar'));
+        $this->assertTrue($container->getAlias('bar')->isPublic());
+
+        $this->assertSame($fooDefinition, $container->getDefinition('foo.extended.inner'));
+        $this->assertFalse($container->getDefinition('foo.extended.inner')->isPublic());
+
+        $this->assertSame($barDefinition, $container->getDefinition('bar.yoo'));
+        $this->assertFalse($container->getDefinition('bar.yoo')->isPublic());
+
+        $this->assertNull($fooExtendedDefinition->getDecoratedService());
+        $this->assertNull($barExtendedDefinition->getDecoratedService());
+    }
+
+    public function testProcessWithAlias()
+    {
+        $container = new ContainerBuilder();
+        $container
+            ->register('foo')
+            ->setPublic(true)
+        ;
+        $container->setAlias('foo.alias', new Alias('foo', false));
+        $fooExtendedDefinition = $container
+            ->register('foo.extended')
+            ->setPublic(true)
+            ->setDecoratedService('foo.alias')
+        ;
+
+        $this->process($container);
+
+        $this->assertEquals('foo.extended', $container->getAlias('foo.alias'));
+        $this->assertFalse($container->getAlias('foo.alias')->isPublic());
+
+        $this->assertEquals('foo', $container->getAlias('foo.extended.inner'));
+        $this->assertFalse($container->getAlias('foo.extended.inner')->isPublic());
+
+        $this->assertNull($fooExtendedDefinition->getDecoratedService());
+    }
+
+    protected function process(ContainerBuilder $container)
+    {
+        $repeatedPass = new DecoratorServicePass();
+        $repeatedPass->process($container);
+    }
+}
diff --git a/src/Symfony/Component/DependencyInjection/Tests/DefinitionTest.php b/src/Symfony/Component/DependencyInjection/Tests/DefinitionTest.php
index 4ffd7c0792..9b4cf21ff9 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/DefinitionTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/DefinitionTest.php
@@ -62,6 +62,26 @@ class DefinitionTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('foo', $def->getClass(), '->getClass() returns the class name');
     }
 
+    public function testSetGetDecoratedService()
+    {
+        $def = new Definition('stdClass');
+        $this->assertNull($def->getDecoratedService());
+        $def->setDecoratedService('foo', 'foo.renamed');
+        $this->assertEquals(array('foo', 'foo.renamed'), $def->getDecoratedService());
+        $def->setDecoratedService(null);
+        $this->assertNull($def->getDecoratedService());
+
+        $def = new Definition('stdClass');
+        $def->setDecoratedService('foo');
+        $this->assertEquals(array('foo', null), $def->getDecoratedService());
+        $def->setDecoratedService(null);
+        $this->assertNull($def->getDecoratedService());
+
+        $def = new Definition('stdClass');
+        $this->setExpectedException('InvalidArgumentException', 'The decorated service inner name for "foo" must be different than the service name itself.');
+        $def->setDecoratedService('foo', 'foo');
+    }
+
     /**
      * @covers Symfony\Component\DependencyInjection\Definition::setArguments
      * @covers Symfony\Component\DependencyInjection\Definition::getArguments
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Dumper/XmlDumperTest.php b/src/Symfony/Component/DependencyInjection/Tests/Dumper/XmlDumperTest.php
index 9ec3438db2..d3116b0a30 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Dumper/XmlDumperTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Dumper/XmlDumperTest.php
@@ -66,7 +66,7 @@ class XmlDumperTest extends \PHPUnit_Framework_TestCase
 
     public function testDumpAnonymousServices()
     {
-        include self::$fixturesPath.'/containers/container11.php';
+        $container = include self::$fixturesPath.'/containers/container11.php';
         $dumper = new XmlDumper($container);
         $this->assertEquals("<?xml version=\"1.0\" encoding=\"utf-8\"?>
 <container xmlns=\"http://symfony.com/schema/dic/services\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd\">
@@ -87,7 +87,7 @@ class XmlDumperTest extends \PHPUnit_Framework_TestCase
 
     public function testDumpEntities()
     {
-        include self::$fixturesPath.'/containers/container12.php';
+        $container = include self::$fixturesPath.'/containers/container12.php';
         $dumper = new XmlDumper($container);
         $this->assertEquals("<?xml version=\"1.0\" encoding=\"utf-8\"?>
 <container xmlns=\"http://symfony.com/schema/dic/services\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd\">
@@ -100,4 +100,35 @@ class XmlDumperTest extends \PHPUnit_Framework_TestCase
 </container>
 ", $dumper->dump());
     }
+
+    /**
+     * @dataProvider provideDecoratedServicesData
+     */
+    public function testDumpDecoratedServices($expectedXmlDump, $container)
+    {
+        $dumper = new XmlDumper($container);
+        $this->assertEquals($expectedXmlDump, $dumper->dump());
+    }
+
+    public function provideDecoratedServicesData()
+    {
+        $fixturesPath = realpath(__DIR__.'/../Fixtures/');
+
+        return array(
+            array("<?xml version=\"1.0\" encoding=\"utf-8\"?>
+<container xmlns=\"http://symfony.com/schema/dic/services\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd\">
+  <services>
+    <service id=\"foo\" class=\"FooClass\Foo\" decorates=\"bar\" decoration-inner-name=\"bar.woozy\"/>
+  </services>
+</container>
+", include $fixturesPath.'/containers/container15.php'),
+            array("<?xml version=\"1.0\" encoding=\"utf-8\"?>
+<container xmlns=\"http://symfony.com/schema/dic/services\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:schemaLocation=\"http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd\">
+  <services>
+    <service id=\"foo\" class=\"FooClass\Foo\" decorates=\"bar\"/>
+  </services>
+</container>
+", include $fixturesPath.'/containers/container16.php'),
+        );
+    }
 }
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container15.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container15.php
new file mode 100644
index 0000000000..bb41ea3c4f
--- /dev/null
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container15.php
@@ -0,0 +1,11 @@
+<?php
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+$container = new ContainerBuilder();
+$container
+    ->register('foo', 'FooClass\\Foo')
+    ->setDecoratedService('bar', 'bar.woozy')
+;
+
+return $container;
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container16.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container16.php
new file mode 100644
index 0000000000..67b4d353db
--- /dev/null
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container16.php
@@ -0,0 +1,11 @@
+<?php
+
+use Symfony\Component\DependencyInjection\ContainerBuilder;
+
+$container = new ContainerBuilder();
+$container
+    ->register('foo', 'FooClass\\Foo')
+    ->setDecoratedService('bar')
+;
+
+return $container;
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container9.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container9.php
index c1fceaf24f..15ccc03d0c 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container9.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/containers/container9.php
@@ -92,5 +92,16 @@ $container
     ->register('configured_service', 'stdClass')
     ->setConfigurator(array(new Reference('configurator_service'), 'configureStdClass'))
 ;
+$container
+    ->register('decorated', 'stdClass')
+;
+$container
+    ->register('decorator_service', 'stdClass')
+    ->setDecoratedService('decorated')
+;
+$container
+    ->register('decorator_service_with_name', 'stdClass')
+    ->setDecoratedService('decorated', 'decorated.pif-pouf')
+;
 
 return $container;
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/graphviz/services9.dot b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/graphviz/services9.dot
index 35a0692caf..6bf53e56b6 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/graphviz/services9.dot
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/graphviz/services9.dot
@@ -16,6 +16,9 @@ digraph sc {
   node_depends_on_request [label="depends_on_request\nstdClass\n", shape=record, fillcolor="#eeeeee", style="filled"];
   node_configurator_service [label="configurator_service\nConfClass\n", shape=record, fillcolor="#eeeeee", style="filled"];
   node_configured_service [label="configured_service\nstdClass\n", shape=record, fillcolor="#eeeeee", style="filled"];
+  node_decorated [label="decorated\nstdClass\n", shape=record, fillcolor="#eeeeee", style="filled"];
+  node_decorator_service [label="decorator_service\nstdClass\n", shape=record, fillcolor="#eeeeee", style="filled"];
+  node_decorator_service_with_name [label="decorator_service_with_name\nstdClass\n", shape=record, fillcolor="#eeeeee", style="filled"];
   node_service_container [label="service_container\nSymfony\\Component\\DependencyInjection\\ContainerBuilder\n", shape=record, fillcolor="#9999ff", style="filled"];
   node_foo2 [label="foo2\n\n", shape=record, fillcolor="#ff9999", style="filled"];
   node_foo3 [label="foo3\n\n", shape=record, fillcolor="#ff9999", style="filled"];
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9.php
index a18f7437fb..0e5f4dc53e 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9.php
@@ -27,6 +27,9 @@ class ProjectServiceContainer extends Container
             'baz' => 'getBazService',
             'configurator_service' => 'getConfiguratorServiceService',
             'configured_service' => 'getConfiguredServiceService',
+            'decorated' => 'getDecoratedService',
+            'decorator_service' => 'getDecoratorServiceService',
+            'decorator_service_with_name' => 'getDecoratorServiceWithNameService',
             'depends_on_request' => 'getDependsOnRequestService',
             'factory_service' => 'getFactoryServiceService',
             'foo' => 'getFooService',
@@ -96,6 +99,45 @@ class ProjectServiceContainer extends Container
         return $instance;
     }
 
+    /**
+     * Gets the 'decorated' service.
+     *
+     * This service is shared.
+     * This method always returns the same instance of the service.
+     *
+     * @return stdClass A stdClass instance.
+     */
+    protected function getDecoratedService()
+    {
+        return $this->services['decorated'] = new \stdClass();
+    }
+
+    /**
+     * Gets the 'decorator_service' service.
+     *
+     * This service is shared.
+     * This method always returns the same instance of the service.
+     *
+     * @return stdClass A stdClass instance.
+     */
+    protected function getDecoratorServiceService()
+    {
+        return $this->services['decorator_service'] = new \stdClass();
+    }
+
+    /**
+     * Gets the 'decorator_service_with_name' service.
+     *
+     * This service is shared.
+     * This method always returns the same instance of the service.
+     *
+     * @return stdClass A stdClass instance.
+     */
+    protected function getDecoratorServiceWithNameService()
+    {
+        return $this->services['decorator_service_with_name'] = new \stdClass();
+    }
+
     /**
      * Gets the 'depends_on_request' service.
      *
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
index 74e518f3e1..fcbe3dcd34 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/php/services9_compiled.php
@@ -37,6 +37,8 @@ class ProjectServiceContainer extends Container
             'bar' => 'getBarService',
             'baz' => 'getBazService',
             'configured_service' => 'getConfiguredServiceService',
+            'decorator_service' => 'getDecoratorServiceService',
+            'decorator_service_with_name' => 'getDecoratorServiceWithNameService',
             'depends_on_request' => 'getDependsOnRequestService',
             'factory_service' => 'getFactoryServiceService',
             'foo' => 'getFooService',
@@ -49,6 +51,7 @@ class ProjectServiceContainer extends Container
         $this->aliases = array(
             'alias_for_alias' => 'foo',
             'alias_for_foo' => 'foo',
+            'decorated' => 'decorator_service_with_name',
         );
     }
 
@@ -108,6 +111,32 @@ class ProjectServiceContainer extends Container
         return $instance;
     }
 
+    /**
+     * Gets the 'decorator_service' service.
+     *
+     * This service is shared.
+     * This method always returns the same instance of the service.
+     *
+     * @return stdClass A stdClass instance.
+     */
+    protected function getDecoratorServiceService()
+    {
+        return $this->services['decorator_service'] = new \stdClass();
+    }
+
+    /**
+     * Gets the 'decorator_service_with_name' service.
+     *
+     * This service is shared.
+     * This method always returns the same instance of the service.
+     *
+     * @return stdClass A stdClass instance.
+     */
+    protected function getDecoratorServiceWithNameService()
+    {
+        return $this->services['decorator_service_with_name'] = new \stdClass();
+    }
+
     /**
      * Gets the 'depends_on_request' service.
      *
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services6.xml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services6.xml
index ffc038234f..7e2753eb7c 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services6.xml
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services6.xml
@@ -50,5 +50,7 @@
     <service id="another_alias_for_foo" alias="foo" public="false" />
     <service id="factory_service" factory-method="getInstance" factory-service="baz_factory" />
     <service id="request" class="Request" synthetic="true" synchronized="true" lazy="true"/>
+    <service id="decorator_service" decorates="decorated" />
+    <service id="decorator_service_with_name" decorates="decorated" decoration-inner-name="decorated.pif-pouf"/>
   </services>
 </container>
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services9.xml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services9.xml
index f9d9d4797b..786bc7aae0 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services9.xml
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services9.xml
@@ -88,6 +88,9 @@
     <service id="configured_service" class="stdClass">
       <configurator service="configurator_service" method="configureStdClass"/>
     </service>
+    <service id="decorated" class="stdClass"/>
+    <service id="decorator_service" class="stdClass" decorates="decorated"/>
+    <service id="decorator_service_with_name" class="stdClass" decorates="decorated" decoration-inner-name="decorated.pif-pouf"/>
     <service id="alias_for_foo" alias="foo"/>
     <service id="alias_for_alias" alias="foo"/>
   </services>
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services6.yml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services6.yml
index d3c793f2e3..420c56d34f 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services6.yml
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services6.yml
@@ -30,3 +30,8 @@ services:
         synthetic: true
         synchronized: true
         lazy: true
+    decorator_service:
+        decorates: decorated
+    decorator_service_with_name:
+        decorates: decorated
+        decoration-inner-name: decorated.pif-pouf
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services9.yml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services9.yml
index 1dd163a259..41cc350f9e 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services9.yml
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/yaml/services9.yml
@@ -79,5 +79,14 @@ services:
     configured_service:
         class: stdClass
         configurator: ['@configurator_service', configureStdClass]
+    decorated:
+        class: stdClass
+    decorator_service:
+        class: stdClass
+        decorates: decorated
+    decorator_service_with_name:
+        class: stdClass
+        decorates: decorated
+        decoration-inner-name: decorated.pif-pouf
     alias_for_foo: @foo
     alias_for_alias: @foo
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
index b1f32e283e..6a660a3af2 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
@@ -229,6 +229,10 @@ class XmlFileLoaderTest extends \PHPUnit_Framework_TestCase
         $this->assertTrue(isset($aliases['another_alias_for_foo']));
         $this->assertEquals('foo', (string) $aliases['another_alias_for_foo']);
         $this->assertFalse($aliases['another_alias_for_foo']->isPublic());
+
+        $this->assertNull($services['request']->getDecoratedService());
+        $this->assertEquals(array('decorated', null), $services['decorator_service']->getDecoratedService());
+        $this->assertEquals(array('decorated', 'decorated.pif-pouf'), $services['decorator_service_with_name']->getDecoratedService());
     }
 
     public function testParsesTags()
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
index 37abca7483..ef28b57798 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/YamlFileLoaderTest.php
@@ -131,6 +131,10 @@ class YamlFileLoaderTest extends \PHPUnit_Framework_TestCase
         $this->assertTrue(isset($aliases['another_alias_for_foo']));
         $this->assertEquals('foo', (string) $aliases['another_alias_for_foo']);
         $this->assertFalse($aliases['another_alias_for_foo']->isPublic());
+
+        $this->assertNull($services['request']->getDecoratedService());
+        $this->assertEquals(array('decorated', null), $services['decorator_service']->getDecoratedService());
+        $this->assertEquals(array('decorated', 'decorated.pif-pouf'), $services['decorator_service_with_name']->getDecoratedService());
     }
 
     public function testExtensions()