diff --git a/composer.json b/composer.json
index dc8eebb..4e15be2 100644
--- a/composer.json
+++ b/composer.json
@@ -15,6 +15,6 @@
         }
     },
     "require": {
-        "symfony/process": "~2.3|~3.0"
+        "symfony/process": "~2.3|~3.0|^4.0"
     }
 }