diff --git a/gemfiles/mongo_mapper.gemfile b/gemfiles/mongo_mapper.gemfile
index 0b35fec..9753a35 100644
--- a/gemfiles/mongo_mapper.gemfile
+++ b/gemfiles/mongo_mapper.gemfile
@@ -18,7 +18,7 @@ end
 platforms :rbx do
   gem 'rubysl', '~> 2.0'
   gem 'racc'
-  gem 'rubysl-test-unit'
+  gem 'minitest'
   gem 'rubinius-developer_tools'
 end