diff --git a/jekyll.gemspec b/jekyll.gemspec
index cd395683..49b8d008 100644
--- a/jekyll.gemspec
+++ b/jekyll.gemspec
@@ -29,6 +29,7 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency('maruku', "~> 0.5")
   s.add_runtime_dependency('kramdown', "~> 0.13.4")
   s.add_runtime_dependency('pygments.rb', "~> 0.3.2")
+  s.add_runtime_dependency('commander', "~> 4.1.3")
 
   s.add_development_dependency('rake', "~> 0.9")
   s.add_development_dependency('rdoc', "~> 3.11")