diff --git a/Rakefile b/Rakefile
index 14cfe0b..50088eb 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,2 +1,32 @@
 require 'bundler'
 Bundler::GemHelper.install_tasks
+
+require 'rspec/core/rake_task'
+
+RSpec::Core::RakeTask.new(:spec)
+
+namespace :spec do
+  desc "Run on three Rubies"
+  task :platforms do
+    current = %x{rvm-prompt v}
+    
+    fail = false
+    %w{1.8.7 1.9.2 ree}.each do |version|
+      puts "Switching to #{version}"
+      Bundler.with_clean_env do
+        system %{bash -c 'source ~/.rvm/scripts/rvm ; rvm #{version} ; bundle install ; bundle exec rake spec'}
+      end
+      if $?.exitstatus != 0
+        fail = true
+        break
+      end
+    end
+
+    system %{rvm #{current}}
+
+    exit (fail ? 1 : 0)
+  end
+end
+
+task :default => 'spec:platforms'
+
diff --git a/spec/lib/jasmine/cli_spec.rb b/spec/lib/jasmine/cli_spec.rb
index 15d2ff7..8415b5e 100644
--- a/spec/lib/jasmine/cli_spec.rb
+++ b/spec/lib/jasmine/cli_spec.rb
@@ -45,8 +45,8 @@ describe Jasmine::CLI do
     let(:test_data) { %w{third fourth} }
 
     before do
-      File.open(GLOBAL_DEFAULTS_FILE, 'w') { |fh| fh.puts global_test_data.join(' ') }
-      File.open(DEFAULTS_FILE, 'w') { |fh| fh.puts test_data.join(' ') }
+      File.open(Jasmine::CLI::GLOBAL_DEFAULTS_FILE, 'w') { |fh| fh.puts global_test_data.join(' ') }
+      File.open(Jasmine::CLI::DEFAULTS_FILE, 'w') { |fh| fh.puts test_data.join(' ') }
     end
 
     it "should read the options" do