diff --git a/jekyll.gemspec b/jekyll.gemspec
index 91173067..012ad01a 100644
--- a/jekyll.gemspec
+++ b/jekyll.gemspec
@@ -63,4 +63,6 @@ Gem::Specification.new do |s|
   s.add_development_dependency('jekyll_test_plugin')
   s.add_development_dependency('jekyll_test_plugin_malicious')
   s.add_development_dependency('rouge', '~> 1.7')
+  s.add_development_dependency('minitest') if RUBY_PLATFORM =~ /cygwin/
+  s.add_development_dependency('test-unit') if RUBY_PLATFORM =~ /cygwin/
 end