diff --git a/lib/Doctrine/Hydrate.php b/lib/Doctrine/Hydrate.php
index 9041b3fb5..6c5037af5 100644
--- a/lib/Doctrine/Hydrate.php
+++ b/lib/Doctrine/Hydrate.php
@@ -179,6 +179,8 @@ class Doctrine_Hydrate extends Doctrine_Object implements Serializable
      */
     public function getRootAlias()
     {
+        $this->getSql();
+
         reset($this->_aliasMap);
 
         return key($this->_aliasMap);