diff --git a/.travis.yml b/.travis.yml
index 14344eb..e7703f9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -4,6 +4,8 @@ node_js:
   - "0.10"
   - "0.12"
   - "iojs"
+  - "4"
+  - "6"
 script:
   - npm test
   - npm run lint