diff --git a/lib/Doctrine/Parser/Yml.php b/lib/Doctrine/Parser/Yml.php
index bbd5c0088..2369b54eb 100644
--- a/lib/Doctrine/Parser/Yml.php
+++ b/lib/Doctrine/Parser/Yml.php
@@ -1,5 +1,7 @@
 <?php
-require_once('spyc.php');
+if (!class_exists('Spyc')) {
+    require_once('spyc.php');
+}
 
 /*
  *  $Id: Yml.php 1080 2007-02-10 18:17:08Z jwage $