diff --git a/template.php b/template.php
index d6d3405..f514530 100644
--- a/template.php
+++ b/template.php
@@ -61,6 +61,11 @@ function lucid_preprocess_html(&$vars) {
   }
   else {
     $vars['doctype'] = '<!DOCTYPE html>' . "\n";
+
+    if (!isset($vars['rdf'])) {
+      $vars['rdf'] = new stdClass();
+    }
+
     $vars['rdf']->version = '';
     $vars['rdf']->namespaces = '';
     $vars['rdf']->profile = '';
