diff --git a/lib/Doctrine/ORM/Mapping/Driver/XmlDriver.php b/lib/Doctrine/ORM/Mapping/Driver/XmlDriver.php
index 0d72c2087..ca2707278 100644
--- a/lib/Doctrine/ORM/Mapping/Driver/XmlDriver.php
+++ b/lib/Doctrine/ORM/Mapping/Driver/XmlDriver.php
@@ -838,6 +838,7 @@ class XmlDriver extends FileDriver
     protected function loadMappingFile($file)
     {
         $result = [];
+        // Note: we do not use `simplexml_load_file()` because of https://bugs.php.net/bug.php?id=62577
         $xmlElement = simplexml_load_string(file_get_contents($file));
 
         if (isset($xmlElement->entity)) {