diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
index 6a6441a39c86..f49c5f11e0ee 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -642,6 +642,7 @@ private function addAssetsSection(ArrayNodeDefinition $rootNode)
                     ->fixXmlConfig('package')
                     ->children()
                         ->arrayNode('packages')
+                            ->normalizeKeys(false)
                             ->useAttributeAsKey('name')
                             ->prototype('array')
                                 ->fixXmlConfig('base_url')
diff --git a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
index 1be4015713dc..91764a642e8d 100644
--- a/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
+++ b/src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php
@@ -211,6 +211,35 @@ public function testAssetsCanBeEnabled()
         $this->assertEquals($defaultConfig, $config['assets']);
     }
 
+    /**
+     * @dataProvider provideValidAssetsPackageNameConfigurationTests
+     */
+    public function testValidAssetsPackageNameConfiguration($packageName)
+    {
+        $processor = new Processor();
+        $configuration = new Configuration(true);
+        $config = $processor->processConfiguration($configuration, [
+            [
+                'assets' => [
+                    'packages' => [
+                        $packageName => [],
+                    ],
+                ],
+            ],
+        ]);
+
+        $this->assertArrayHasKey($packageName, $config['assets']['packages']);
+    }
+
+    public function provideValidAssetsPackageNameConfigurationTests()
+    {
+        return [
+            ['foobar'],
+            ['foo-bar'],
+            ['foo_bar'],
+        ];
+    }
+
     /**
      * @dataProvider provideInvalidAssetConfigurationTests
      */