diff --git a/gradient.gemspec b/gradient.gemspec
index dd180bb..e237a2d 100644
--- a/gradient.gemspec
+++ b/gradient.gemspec
@@ -21,6 +21,7 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency "color", "~> 1.8"
   spec.add_dependency 'nokogiri', '~> 1.6'
+  spec.add_dependency 'scanf', '~> 1.0'
   spec.add_development_dependency "bundler", "~> 1.7"
   spec.add_development_dependency "rake", "~> 10.0"
   spec.add_development_dependency "rspec"