diff --git vars.info vars.info
index fddf3d3..f4d148d 100644
--- vars.info
+++ vars.info
@@ -2,5 +2,6 @@
 name = Variables API
 description = Implement an API to handle persistent variables.
 core = 7.x
+version = 2.0
 files[] = vars.module
 files[] = tests/vars.test
diff --git vars.module vars.module
index 60aa555..5e25282 100644
--- vars.module
+++ vars.module
@@ -188,7 +188,7 @@ class Vars implements ArrayAccess {
     drupal_alter('vars_library_search_directories', $dirs, $context);
 
     foreach ($dirs as $dir) {
-      if (file_exists(DRUPAL_ROOT . $dir) && is_dir(DRUPAL_ROOT . $dir)) {
+      if (file_exists(DRUPAL_ROOT . '/' . $dir) && is_dir(DRUPAL_ROOT . '/' . $dir)) {
         $path[] = $dir;
       }
     }