diff --git a/composer.json b/composer.json
index aa7dee0..d57bdac 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,7 @@
         "symfony/config": "^4.0|^5.0"
     },
     "require-dev": {
-        "phpunit/phpunit": "^8.0"
+        "phpunit/phpunit": "^7.0|^8.0"
     },
     "minimum-stability": "stable",
     "autoload": {