diff --git a/.travis.yml b/.travis.yml
index d568a21..59a4a2e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,6 +5,7 @@ php:
   - 5.4
   - 5.5
   - 5.6
+  - hhvm
 
 before_script:
   - composer self-update