diff --git a/.travis.yml b/.travis.yml
index 8f41f070..04eeb437 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,7 @@ rvm:
   - 1.9.3
   - 2.0.0
   - 2.1.2
+  - 2.2.2
   # optional
   - jruby-19mode
   - rbx-19mode
diff --git a/Gemfile b/Gemfile
index 851fabc2..d1886107 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,2 +1,3 @@
 source 'https://rubygems.org'
 gemspec
+gem "test-unit"