diff --git a/.travis.yml b/.travis.yml
index 1f4df12..366e378 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,6 +2,8 @@ rvm:
   - 1.9.2
   - 1.9.3
   - 1.8.7
+  - rbx-18mode
+  - rbx-19mode
 notifications:
   recipients:
     - cowboyd@thefrontside.net