diff --git a/composer.json b/composer.json
index 7e1ca42..9ce3bef 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
         }
     ],
     "require": {
-        "symfony/config": "^3.4",
+        "symfony/config": "^3.4 || ^4.0",
         "symfony/console": "^3.4",
         "symfony/dependency-injection": "^3.4",
         "symfony/filesystem": "^3.4",