diff --git a/src/Symfony/Bridge/PhpUnit/composer.json b/src/Symfony/Bridge/PhpUnit/composer.json
index e5395bccd7..a52dacc867 100644
--- a/src/Symfony/Bridge/PhpUnit/composer.json
+++ b/src/Symfony/Bridge/PhpUnit/composer.json
@@ -24,7 +24,7 @@
         "symfony/error-handler": "For tracking deprecated interfaces usages at runtime with DebugClassLoader"
     },
     "conflict": {
-        "phpunit/phpunit": "<5.4.3"
+        "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0"
     },
     "autoload": {
         "files": [ "bootstrap.php" ],