diff --git a/Gemfile b/Gemfile
index cc1798e63..452a95d61 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,3 +9,10 @@ gem "rspec-expectations", :path => "."
 gem "rspec-core", :path => "../rspec-core"
 gem "rspec-mocks", :path => "../rspec-mocks"
 gem "watchr"
+
+case RUBY_VERSION
+when /^1\.9/
+  gem 'ruby-debug19'
+when /^1\.8/
+  gem 'ruby-debug'
+end