diff --git a/composer.json b/composer.json
index 8f10b09..2dd2a6f 100644
--- a/composer.json
+++ b/composer.json
@@ -13,7 +13,7 @@
         }
     ],
     "require-dev": {
-        "phpunit/phpunit": "^5.0|^6.0|^7.0|^8.0|^9.0|^10.5|^11.0"
+        "phpunit/phpunit": "^5.0|^6.0|^7.0|^8.0|^9.0|^10.5|^11.0|^12.0"
     },
     "require": {
         "ext-pcntl": "*",