diff --git a/outputxml.php b/outputxml.php
index 9a4f7cc..06a23c9 100644
--- a/outputxml.php
+++ b/outputxml.php
@@ -17,13 +17,22 @@ class outputxml extends output
     @header('Cache-Control: post-check=0, pre-check=0', false);
     @header('Pragma: no-cache');
     @header ("Content-Type: text/xml");
-    $xml = new SimpleXMLElement ("<?xml version=\"1.0\"?><root></root>");
-    // function call to convert array to xml
-    if (!is_array ($data))
-      $data = array ($data);
-    $this->array_to_xml ($data, $xml);
-    //saving generated xml file
-    print $xml->asXML();
+    if (is_string ($data) && substr ($data, 0, 6) === "<?xml ")
+    {
+      // If data is already in XML, do not modify it !
+      // Like RSS, the XML is constructed by the rss class
+      echo $data;
+    }
+    else
+    {
+      $xml = new SimpleXMLElement ("<?xml version=\"1.0\"?><root></root>");
+      // function call to convert array to xml
+      if (!is_array ($data))
+        $data = array ($data);
+      $this->array_to_xml ($data, $xml);
+      //saving generated xml file
+      print $xml->asXML();
+    }
     if (!defined ("PHPUNIT"))
       exit;
   }