diff --git a/git_deploy.module b/git_deploy.module
index 3cb905e..3535912 100644
--- a/git_deploy.module
+++ b/git_deploy.module
@@ -146,8 +146,8 @@ function git_deploy_update_status_alter(&$projects) {
       // Make sure Git operates in the right directory.
       $git = 'git -C ' . drupal_get_path(preg_replace('/-disabled$/', '', $project_info['project_type']), key($project_info['includes']));
       // Verify that we are in a Git repository.
-      $directory = exec("$git rev-parse --show-toplevel 2> " . GIT_DEPLOY_ERROR_DUMP);
-      if (!empty($directory)) {
+      exec("$git rev-parse 2> " . GIT_DEPLOY_ERROR_DUMP, $output, $return_val);
+      if ($return_val === 0) {
         $version = $project_info['existing_version'];
         if (isset($project_info['releases'][$version])) {
           $release = $project_info['releases'][$version];