diff --git a/Capfile b/Capfile
index 1f07fb9..aaa5007 100644
--- a/Capfile
+++ b/Capfile
@@ -7,6 +7,8 @@ require 'capistrano/deploy'
 require 'capistrano/scm/git'
 install_plugin Capistrano::SCM::Git
 
+require 'stringio'
+
 require 'capistrano/maintenance'
 
 require 'dlss/docker/capistrano'