diff --git a/Tests/Functional/ConfigurationTest.php b/Tests/Functional/ConfigurationTest.php
index 4c0b5ff53..44f3df7ba 100644
--- a/Tests/Functional/ConfigurationTest.php
+++ b/Tests/Functional/ConfigurationTest.php
@@ -40,7 +40,7 @@ public function testToolbar()
                 '/_profiler/empty/search/results?limit=10',
                 [],
                 [],
-                ['HTTP_Accept' => 'application/json']
+                ['HTTP_Accept' => 'application/xml']
             );
 
         $this->assertSame('text/html; charset=UTF-8', $client->getResponse()->headers->get('Content-Type'));