diff --git a/Gemfile b/Gemfile
index a3f70b9..c718a45 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,6 +1,7 @@
 source "http://rubygems.org"
 
 gem 'nokogiri'
+gem 'zipruby'
 
 # Specify your gem's dependencies in comicbox.gemspec
 gemspec