diff --git a/modules/node/views_plugin_row_node_rss.inc b/modules/node/views_plugin_row_node_rss.inc
index a933ff8f35a1570fd02dda6277da5ff32c61f059..189ff1f2ea7ac919066b1a530776963c70b44803 100644
--- a/modules/node/views_plugin_row_node_rss.inc
+++ b/modules/node/views_plugin_row_node_rss.inc
@@ -135,11 +135,10 @@ class views_plugin_row_node_rss extends views_plugin_row {
 
     if (!empty($node->rss_namespaces)) {
       $this->view->style_plugin->namespaces = array_merge($this->view->style_plugin->namespaces, $node->rss_namespaces);
-    } else {
+    } else if (module_exists('rdf')) {
       $this->view->style_plugin->namespaces = array_merge($this->view->style_plugin->namespaces, rdf_get_namespaces());
     }
 
-
     // Hide the links if desired.
     if (!$this->options['links']) {
       hide($build['links']);