diff --git a/composer.json b/composer.json
index 4f36fe3..475b6a2 100644
--- a/composer.json
+++ b/composer.json
@@ -34,7 +34,7 @@
         "phan/phan": "^5.4.2",
         "phpstan/phpstan": "^1.0",
         "phpstan/phpstan-strict-rules": "^1.0",
-        "phpunit/phpunit": "^7.5 || ^8.5 || ^9.6",
+        "phpunit/phpunit": "^7.5.20 || ^8.5.36 || ^9.6.15",
         "psalm/plugin-phpunit": "^0.18",
         "vimeo/psalm": "^4.30"
     },