diff --git a/.travis.yml b/.travis.yml
index 08d76d4b69..7280d8cd44 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -42,6 +42,7 @@ before_script:
        composer require 'phpunit/phpunit:~6.3';
       ;;
     "hhvm")
+       composer require 'phpunit/phpunit:~6.3';
        ;;
     esac
   #- php -m