diff --git a/lib/gitlab/upgrader.rb b/lib/gitlab/upgrader.rb
index 0fe4888..0846359 100644
--- a/lib/gitlab/upgrader.rb
+++ b/lib/gitlab/upgrader.rb
@@ -1,3 +1,4 @@
+require_relative "popen"
 require_relative "version_info"
 
 module Gitlab
--
libgit2 0.21.2