diff --git a/lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php b/lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php
index fb45516eb..853f84efe 100644
--- a/lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php
+++ b/lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php
@@ -41,10 +41,10 @@ class XmlExporter extends AbstractExporter
      */
     public function exportClassMetadata(ClassMetadataInfo $metadata): string
     {
-        $xml = new SimpleXmlElement("<?xml version=\"1.0\" encoding=\"utf-8\"?><doctrine-mapping ".
-            "xmlns=\"http://doctrine-project.org/schemas/orm/doctrine-mapping\" " .
-            "xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" ".
-            "xsi:schemaLocation=\"http://doctrine-project.org/schemas/orm/doctrine-mapping http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd\" />");
+        $xml = new SimpleXmlElement('<?xml version="1.0" encoding="utf-8"?><doctrine-mapping ' .
+            'xmlns="http://doctrine-project.org/schemas/orm/doctrine-mapping" ' .
+            'xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" ' .
+            'xsi:schemaLocation="http://doctrine-project.org/schemas/orm/doctrine-mapping http://doctrine-project.org/schemas/orm/doctrine-mapping.xsd" />');
 
         if ($metadata->isMappedSuperclass) {
             $root = $xml->addChild('mapped-superclass');