diff --git a/composer.json b/composer.json
index 7e1ca42..1e0b50e 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
         "symfony/console": "^3.4",
         "symfony/dependency-injection": "^3.4",
         "symfony/filesystem": "^3.4",
-        "symfony/yaml": "^3.4",
+        "symfony/yaml": "^3.4 || ^4.0",
         "tightenco/collect": "^5.4"
     },
     "require-dev": {