diff --git a/.travis.yml b/.travis.yml
index 6f303cf..e15147b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,6 +3,7 @@ php:
   - 5.3
   - 5.4
   - 5.5
+  - hhvm
 branches:
   except:
     - php-52