diff --git a/module/VuFind/src/VuFind/Controller/OaiController.php b/module/VuFind/src/VuFind/Controller/OaiController.php
index 0fcd801c2da941228e45715ebe7cd5c94c33c0a1..0fb4a866b7aeb8e5b67d931ae68c2a06c3fe5465 100644
--- a/module/VuFind/src/VuFind/Controller/OaiController.php
+++ b/module/VuFind/src/VuFind/Controller/OaiController.php
@@ -113,7 +113,7 @@ class OaiController extends AbstractBase
 
         // Return response:
         $headers = $response->getHeaders();
-        $headers->addHeaderLine('Content-type', 'text/xml');
+        $headers->addHeaderLine('Content-type', 'text/xml; charset=UTF-8');
         $response->setContent($xml);
         return $response;
     }