diff --git a/src/Symfony/Component/DomCrawler/Form.php b/src/Symfony/Component/DomCrawler/Form.php
index 7f44a5be5e253..762c824108f75 100644
--- a/src/Symfony/Component/DomCrawler/Form.php
+++ b/src/Symfony/Component/DomCrawler/Form.php
@@ -346,7 +346,8 @@ protected function setNode(\DOMNode $node)
             if ($node->hasAttribute('form')) {
                 // if the node has the HTML5-compliant 'form' attribute, use it
                 $formId = $node->getAttribute('form');
-                $form = $node->ownerDocument->getElementById($formId);
+                $xp = new \DOMXPath($node->ownerDocument);
+                $form = $xp->query("//*[@id='{$formId}']")->item(0);
                 if (null === $form) {
                     throw new \LogicException(sprintf('The selected node has an invalid form attribute (%s).', $formId));
                 }