diff --git a/libs/Tree/Builder.php b/libs/Tree/Builder.php
index 0980d34..7af752e 100644
--- a/libs/Tree/Builder.php
+++ b/libs/Tree/Builder.php
@@ -190,7 +190,7 @@ class Builder
 
         if ($title == 'index') {
             // TODO :: clarify the difference between 'index' and '_index'
-            $page->setName('_index' . pathinfo($path, PATHINFO_EXTENSION));
+            $page->setName('_index.' . pathinfo($path, PATHINFO_EXTENSION));
             $page->setTitle($parent->getTitle());
         } else {
             $page->setName($path);