diff --git a/src/SPC/builder/extension/parallel.php b/src/SPC/builder/extension/parallel.php
new file mode 100644
index 00000000..8fdf1824
--- /dev/null
+++ b/src/SPC/builder/extension/parallel.php
@@ -0,0 +1,21 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SPC\builder\extension;
+
+use SPC\builder\Extension;
+use SPC\exception\WrongUsageException;
+use SPC\util\CustomExt;
+
+#[CustomExt('parallel')]
+class parallel extends Extension
+{
+    public function getConfigureArg(): string
+    {
+        if (!$this->builder->getOption('enable-zts')) {
+            throw new WrongUsageException('ext-parallel must be built with ZTS builds. Use "--enable-zts" option!');
+        }
+        return parent::getConfigureArg(); // TODO: Change the autogenerated stub
+    }
+}