diff --git a/Gemfile b/Gemfile
index a23c47f..dc7abd2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -16,6 +16,7 @@ end
 gem 'nokogiri', RUBY_VERSION < '2.1' ? '~> 1.6.0' : '>= 1.7'
 gem 'loofah', RUBY_VERSION < '2.5' ? '< 2.21.0' : '>= 0'
 gem 'selenium-webdriver'
+gem 'bigdecimal'
 
 rails_version = ENV['RAILS_VERSION'] || '∞'