Gemfile in rouge-0.2.1 vs Gemfile in rouge-0.2.2

@@ -6,10 +6,11 @@
 gem 'sexp_processor', '~> 3.0'
 gem 'wrong', '~> 0.6.2'
 
 gem 'rake'
 
-gem 'redcarpet'
+# don't try to install redcarpet under jruby
+gem 'redcarpet', :platforms => :ruby
 
 # for visual tests
 gem 'sinatra'
 
 # docs