diff --git a/.travis.yml b/.travis.yml
index 6bf73a6..ab7ec22 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -6,6 +6,9 @@ php:
   - 5.6
   - hhvm
 
+services:
+  - mongodb
+
 before_script:
   - sh -c 'if [ "$TRAVIS_PHP_VERSION" != "hhvm" ]; then phpenv config-add config/config.ini; fi;'
   - composer self-update