diff --git a/composer.json b/composer.json
index a67c13d..dcc74b1 100644
--- a/composer.json
+++ b/composer.json
@@ -20,7 +20,7 @@
         "friendsofphp/php-cs-fixer": "^2.16",
         "overtrue/phplint": "^2.3",
         "phpstan/phpstan": "0.*",
-        "phpunit/phpunit": "^8 || ^9",
+        "phpunit/phpunit": "^7 || ^8 || ^9",
         "squizlabs/php_codesniffer": "^3.5"
     },
     "autoload": {