diff --git a/composer.json b/composer.json
--- a/composer.json
+++ b/composer.json
@@ -10,12 +10,12 @@
     }
   ],
   "require": {
-    "php": ">=7.1.0",
+    "php": ">=7.3.0",
     "netresearch/jsonmapper": "^1.1.1",
     "vlucas/phpdotenv": "^2.4"
   },
   "require-dev": {
-    "phpunit/phpunit": "^6.4"
+    "phpunit/phpunit": "^9.5"
   },
   "autoload": {
     "psr-4": {