diff --git a/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php b/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
index 58c8301065..f688cfab73 100644
--- a/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
+++ b/src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php
@@ -307,12 +307,14 @@ class XmlFileLoader extends FileLoader
     {
         $arguments = array();
         foreach ($this->getChildren($node, $name) as $arg) {
-            if ($nameAttr = $arg->getAttribute('name')) {
-                $arg->setAttribute('key', $nameAttr);
+            if ($arg->hasAttribute('name')) {
+                $arg->setAttribute('key', $arg->getAttribute('name'));
             }
 
-            if (!$key = $arg->getAttribute('key')) {
+            if (!$arg->hasAttribute('key')) {
                 $key = !$arguments ? 0 : max(array_keys($arguments)) + 1;
+            } else {
+                $key = $arg->getAttribute('key');
             }
 
             // parameter keys are case insensitive
@@ -322,8 +324,8 @@ class XmlFileLoader extends FileLoader
 
             // this is used by DefinitionDecorator to overwrite a specific
             // argument of the parent definition
-            if ($index = $arg->getAttribute('index')) {
-                $key = 'index_'.$index;
+            if ($arg->hasAttribute('index')) {
+                $key = 'index_'.$arg->getAttribute('index');
             }
 
             switch ($arg->getAttribute('type')) {
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services14.xml b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services14.xml
new file mode 100644
index 0000000000..73446214e4
--- /dev/null
+++ b/src/Symfony/Component/DependencyInjection/Tests/Fixtures/xml/services14.xml
@@ -0,0 +1,19 @@
+<?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="monolog.logger" parent="monolog.logger_prototype" public="false">
+            <argument index="0">app</argument>
+        </service>
+
+        <service id="logger" alias="monolog.logger" />
+
+        <service id="monolog.logger" parent="monolog.logger_prototype" public="false">
+            <argument index="0">app</argument>
+        </service>
+        <service id="monolog.logger_prototype" class="Symfony\Bridge\Monolog\Logger" abstract="true">
+            <argument /><!-- Channel -->
+        </service>
+    </services>
+</container>
diff --git a/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php b/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
index 1721bc3d9c..c9ad753c9b 100644
--- a/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
+++ b/src/Symfony/Component/DependencyInjection/Tests/Loader/XmlFileLoaderTest.php
@@ -444,4 +444,13 @@ class XmlFileLoaderTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals(1, count($services['foo']->getTag('foo.tag')), '->load parses <srv:tag> elements');
         $this->assertEquals(array(array('setBar', array('foo'))), $services['foo']->getMethodCalls(), '->load() parses the <srv:call> tag');
     }
+
+    public function testLoadIndexedArguments()
+    {
+        $container = new ContainerBuilder();
+        $loader = new XmlFileLoader($container, new FileLocator(self::$fixturesPath.'/xml'));
+        $loader->load('services14.xml');
+
+        $this->assertEquals(array('index_0' => 'app'), $container->findDefinition('logger')->getArguments());
+    }
 }