diff --git a/jekyll.gemspec b/jekyll.gemspec
index 3d10f193..0de0c969 100644
--- a/jekyll.gemspec
+++ b/jekyll.gemspec
@@ -42,6 +42,7 @@ Gem::Specification.new do |s|
   s.add_development_dependency('redcarpet', "~> 2.1.1")
   s.add_development_dependency('launchy', "~> 2.1.2")
   s.add_development_dependency('simplecov', "~> 0.7")
+  s.add_development_dependency('simplecov-gem-adapter', "~> 1.0.1")
   # migrator dependencies:
   s.add_development_dependency('sequel', "~> 3.42")
   s.add_development_dependency('htmlentities', "~> 4.3")