diff --git a/composer.json b/composer.json
index 7a1505c7c904df550cff77337675bf8dba10cd5d..5c0251ec5b55605be7ba58cf325e70a3722f4cf2 100644
--- a/composer.json
+++ b/composer.json
@@ -14,6 +14,7 @@
     "ext-json": "*",
     "beberlei/assert": "^3.2",
     "friendsofphp/php-cs-fixer": "^2.16",
+    "symfony/event-dispatcher-contracts": "^1.1",
     "symfony/cache": "^4.3",
     "symfony/cache-contracts": "^1.1"
   },