diff --git a/.travis.yml b/.travis.yml
index 3a4ae8a..2683604 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,8 +6,7 @@ addons:
     packages:
     - libgecode-dev
 rvm:
-- "2.1"
-- "2.2"
+- 2.3.1
 gemfile:
 - gemfiles/default.gemfile
 - gemfiles/master.gemfile