Gemfile in flapjack-0.9.5 vs Gemfile in flapjack-0.9.6

@@ -18,8 +18,11 @@
   gem 'rb-fsevent'
   gem 'guard-rspec'
   gem 'guard-cucumber'
   gem 'fuubar'
   gem 'simplecov', :require => false
-  gem 'debugger-ruby_core_source', '>= 1.3.4' # required for perftools
-  gem 'perftools.rb'
+
+ if RUBY_VERSION.split('.')[0] == '1' && RUBY_VERSION.split('.')[1] == '9'
+    gem 'debugger-ruby_core_source', '>= 1.3.4' # required for perftools.rb
+    gem 'perftools.rb'
+  end
 end