diff --git a/squib.gemspec b/squib.gemspec
index b1e8aca..08eae4d 100644
--- a/squib.gemspec
+++ b/squib.gemspec
@@ -30,6 +30,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'cairo', '~> 1.14.3'
   spec.add_runtime_dependency 'pango', '~> 3.0.1'
   spec.add_runtime_dependency 'roo', '~> 2.2.0'
+  spec.add_runtime_dependency 'nokogiri', '~> 1.6.7'
   spec.add_runtime_dependency 'rsvg2', '~> 3.0.0'
   spec.add_runtime_dependency 'mercenary', '~> 0.3.4'
   spec.add_runtime_dependency 'ruby-progressbar', '~> 1.6'