diff --git a/src/SPC/builder/extension/password_argon2.php b/src/SPC/builder/extension/password_argon2.php
new file mode 100644
index 00000000..fb3c4b04
--- /dev/null
+++ b/src/SPC/builder/extension/password_argon2.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SPC\builder\extension;
+
+use SPC\builder\Extension;
+use SPC\exception\RuntimeException;
+use SPC\util\CustomExt;
+
+#[CustomExt('password-argon2')]
+class password_argon2 extends Extension
+{
+    public function runCliCheck(): void
+    {
+        [$ret] = shell()->execWithResult(BUILD_ROOT_PATH . '/bin/php -r "assert(defined(\'PASSWORD_ARGON2I\'));"');
+        if ($ret !== 0) {
+            throw new RuntimeException('extension ' . $this->getName() . ' failed sanity check');
+        }
+    }
+}