diff --git a/.travis.yml b/.travis.yml
index afe251b2..0be6ba13 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,7 @@ php:
   - 5.3
   - 5.4
   - 5.5
+  - hhvm
 
 env:
   global:
@@ -14,7 +15,7 @@ env:
     - secure: "jtQTZKQBnzUlp/jz7NlM6470ZDnLGVAs53sgvIm4tcYqf9TWSXSXjIYvFsrS\nKPR2eyZaAevYysUkIGRFTUXTlG6tC36YngMp9+6FPxASl8mnGXsTbKcm613B\n59vD3242pgIgqhhmgFQ0c8gbvnE8PuF2aS4/hluP3r+AxhWN56E="
 
 before_script:
-  - travis/install-php-extensions.sh
+  - sh -c "if [ '$TRAVIS_PHP_VERSION' != 'hhvm' ]; then travis/install-php-extensions.sh; fi"
   - sh -c "if [ '$TRAVIS_PHP_VERSION' = '5.5' ]; then composer install --dev --no-interaction; fi"
 
 script: