diff --git a/composer.json b/composer.json
index d4e4eca..96e4caa 100644
--- a/composer.json
+++ b/composer.json
@@ -15,6 +15,11 @@
         }
     ],
     "bin": [ "bin/dataset-info" ],
+    "require": {
+        "php": "^7.4|^8.0",
+        "ext-simplexml": "*",
+        "ext-json": "*"
+    },
     "require-dev": {
         "phpunit/phpunit": "^9.5",
         "phpstan/phpstan": "^1.8"