diff --git a/rscons.gemspec b/rscons.gemspec
index 3f2b3fd..e95d4b4 100644
--- a/rscons.gemspec
+++ b/rscons.gemspec
@@ -24,4 +24,5 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency "rake"
   gem.add_development_dependency "simplecov"
   gem.add_development_dependency "yard"
+  gem.add_development_dependency "redcarpet"
 end