diff --git a/git_deploy.module b/git_deploy.module
index eba341b..e186b51 100644
--- a/git_deploy.module
+++ b/git_deploy.module
@@ -156,7 +156,13 @@ function _git_deploy_version_alter(&$version, $git_dir, $file) {
     // the .info files, which invokes the hook that leads here.
     if (empty($available)) {
       $cache = _update_cache_get('update_available_releases');
-      $available = $cache->data;
+      if (empty($cache->data)) {
+        drupal_set_message('You need to run the update.module check for new data from drupal.org.');
+        break;
+      }
+      else {
+        $available = $cache->data;
+      }
     }
     $project = update_get_project_name($file);
     if (isset($available[$project]['releases'])) {