diff --git a/.travis.yml b/.travis.yml
index 661decb25..d2a354604 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -37,6 +37,9 @@ matrix:
         - SYMFONY_VERSION=dev-master
         - STABILITY=dev
     - php: nightly
+      env:
+        - SYMFONY_VERSION=4.0.*
+        - COMPOSER_FLAGS="--ignore-platform-reqs"
   allow_failures:
     - env:
         - ENABLE_CODE_COVERAGE="true"
diff --git a/composer.json b/composer.json
index 125741cec..3ee20cf59 100644
--- a/composer.json
+++ b/composer.json
@@ -36,6 +36,7 @@
         "doctrine/cache": "^1.1",
         "doctrine/orm": "^2.3",
         "enqueue/enqueue-bundle": "^0.7|^0.8",
+        "friendsofphp/php-cs-fixer": "^2.10",
         "league/flysystem": "^1.0",
         "psr/log": "^1.0",
         "symfony/browser-kit": "^3.0|^4.0",