diff --git a/.travis.yml b/.travis.yml
index 186eb46e9..d59e0d8b7 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,6 +16,7 @@ matrix:
   include:
   - rvm: 1.9.3
   - rvm: 2.0
+  - rvm: 2.1.8
   - rvm: 2.2
     script: bundle exec rake $SUITE
     env: SUITE="lint test test:functional"
diff --git a/Gemfile b/Gemfile
index 38d6796b7..a90255b87 100644
--- a/Gemfile
+++ b/Gemfile
@@ -8,8 +8,9 @@ if Gem::Version.new(RUBY_VERSION) <= Gem::Version.new('1.9.3')
   gem 'net-ssh', '~> 2.9'
 end
 
-if Gem::Version.new(RUBY_VERSION) <= Gem::Version.new('2.1.0')
+if Gem::Version.new(RUBY_VERSION) < Gem::Version.new('2.2.0')
   gem 'json', '~> 1.8'
+  gem 'rack', '< 2.0'
 end
 
 # TODO: ffi 1.9.11 is currently erroneous on windows tests