diff --git a/composer.json b/composer.json
index e64e313928..48b257df80 100644
--- a/composer.json
+++ b/composer.json
@@ -66,7 +66,7 @@
         "symfony/phpunit-bridge": "^3.4.11"
     },
     "conflict": {
-        "symfony/symfony": "3.4.9",
+        "symfony/symfony": "3.4.9||3.4.12",
         "doctrine/dbal": "2.7.0"
     },
     "scripts": {