diff --git a/Tests/Functional/DependencyInjection/FOSElasticaExtensionTest.php b/Tests/Functional/DependencyInjection/FOSElasticaExtensionTest.php
index a02c35e..06676ef 100644
--- a/Tests/Functional/DependencyInjection/FOSElasticaExtensionTest.php
+++ b/Tests/Functional/DependencyInjection/FOSElasticaExtensionTest.php
@@ -30,7 +30,8 @@ class FOSElasticaExtensionTest extends \PHPUnit_Framework_TestCase
 
         $persisterCallDefinition = $containerBuilder->getDefinition('fos_elastica.object_persister.test_index.child_field');
 
-        $arguments = $persisterCallDefinition->getArguments()['index_3'];
+        $arguments = $persisterCallDefinition->getArguments();
+        $arguments = $arguments['index_3'];
 
         $this->assertArrayHasKey('_parent', $arguments);
         $this->assertEquals('parent_field', $arguments['_parent']['type']);