diff --git a/template.php b/template.php
index 082de0c..90ef00c 100644
--- a/template.php
+++ b/template.php
@@ -71,9 +71,12 @@ function samara_preprocess_page(&$vars) {
   }
 
   // Add $primary_nav variable, unlike built-in $main_menu variable it supports drop-down menus
+  $vars['primary_nav'] = FALSE;
+  
   if (!empty($vars['main_menu'])) {
-    $menu_tree = menu_tree(variable_get('menu_main_links_source', 'main-menu'));
-    $vars['primary_nav'] = $menu_tree ? render($menu_tree) : FALSE;
+    if ($menu_tree = menu_tree(variable_get('menu_main_links_source', 'main-menu'))) {
+      $vars['primary_nav'] = render($menu_tree);
+    }
   }
 
   if (!empty($vars['secondary_menu'])) {