diff --git a/sample_app/Gemfile b/sample_app/Gemfile
index d67a479..b68417a 100644
--- a/sample_app/Gemfile
+++ b/sample_app/Gemfile
@@ -38,6 +38,7 @@ group :test do
   gem 'minitest-reporters',       '1.3.8'
   gem 'guard',                    '2.16.2'
   gem 'guard-minitest',           '2.4.6'
+  gem 'rexml',                    '3.2.5'
 end
 
 group :production do