diff --git a/vagrant.drush.inc b/vagrant.drush.inc
index 33ad804..65c9de9 100644
--- a/vagrant.drush.inc
+++ b/vagrant.drush.inc
@@ -38,7 +38,7 @@ function vagrant_drush_init() {
     // Check if Vagrant is installed
     if (!isset($cache['vagrant_path'])) {
       $vagrant_path = drush_shell_exec_output(drush_shell_exec('which vagrant'));
-      drush_cache_set('vagrant_path', $vagrant_path[0], 'vagrant', DRUSH_CACHE_TEMPORARY);
+      $cache = drush_cache_set('vagrant_path', $vagrant_path[0], 'vagrant', DRUSH_CACHE_TEMPORARY);
     }
     if (!isset($cache['vagrant_path']->data) && !isset($vagrant_path)) {
       drush_log(dt('*** You have installed Drush Vagrant Integration, but Vagrant does not appear to be installed.