diff --git a/lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php b/lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php
index 8ec4d5cd5..3e936a487 100644
--- a/lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php
+++ b/lib/Doctrine/ORM/Tools/Export/Driver/XmlExporter.php
@@ -217,7 +217,7 @@ class XmlExporter extends AbstractExporter
             if (isset($associationMapping['inversedBy'])) {
                 $associationMappingXml->addAttribute('inversed-by', $associationMapping['inversedBy']);
             }
-        	if (isset($associationMapping['indexBy'])) {
+            if (isset($associationMapping['indexBy'])) {
                 $associationMappingXml->addAttribute('index-by', $associationMapping['indexBy']);
             }
             if (isset($associationMapping['orphanRemoval']) && $associationMapping['orphanRemoval']!==false) {
@@ -331,4 +331,4 @@ class XmlExporter extends AbstractExporter
         $result = $dom->saveXML();
         return $result;
     }
-}
\ No newline at end of file
+}