diff --git a/headless/test-node-load.cjs b/headless/test-node-load.cjs
new file mode 100644
index 000000000..c0360488a
--- /dev/null
+++ b/headless/test-node-load.cjs
@@ -0,0 +1,39 @@
+/**
+ * Smoke test: @xterm/headless loads and runs in Node.js (require).
+ */
+const { strictEqual } = require('node:assert');
+const { Terminal } = require('./lib-headless/xterm-headless.js');
+
+function writeSync(term, data) {
+  return new Promise(resolve => term.write(data, resolve));
+}
+
+function lineEquals(term, index, text) {
+  strictEqual(term.buffer.active.getLine(index).translateToString(true), text);
+}
+
+(async () => {
+  const term = new Terminal({ cols: 80, rows: 24, allowProposedApi: true });
+  strictEqual(term.cols, 80);
+  strictEqual(term.rows, 24);
+
+  await writeSync(term, 'hello from node');
+  lineEquals(term, 0, 'hello from node');
+
+  await writeSync(term, 'foo');
+  await writeSync(term, 'bar');
+  await writeSync(term, '文');
+  lineEquals(term, 0, 'hello from nodefoobar文');
+
+  term.resize(60, 15);
+  strictEqual(term.cols, 60);
+  strictEqual(term.rows, 15);
+
+  term.dispose();
+  strictEqual(term._core._store.isDisposed, true);
+
+  console.log('headless package (CJS): load, write, buffer, resize, dispose OK');
+})().catch(err => {
+  console.error(err);
+  process.exit(1);
+});
diff --git a/headless/test-node-load.mjs b/headless/test-node-load.mjs
new file mode 100644
index 000000000..23aed9827
--- /dev/null
+++ b/headless/test-node-load.mjs
@@ -0,0 +1,29 @@
+/**
+ * Smoke test: @xterm/headless loads and runs in Node.js (ESM + CJS).
+ */
+import { createRequire } from 'node:module';
+import { strictEqual } from 'node:assert';
+
+const require = createRequire(import.meta.url);
+
+function writeSync(term, data) {
+  return new Promise(resolve => term.write(data, resolve));
+}
+
+function lineEquals(term, index, text) {
+  strictEqual(term.buffer.active.getLine(index).translateToString(true), text);
+}
+
+const { Terminal: TerminalEsm } = await import('./lib-headless/xterm-headless.mjs');
+const termEsm = new TerminalEsm({ cols: 80, rows: 24 });
+await writeSync(termEsm, 'esm ok');
+lineEquals(termEsm, 0, 'esm ok');
+termEsm.dispose();
+
+const { Terminal: TerminalCjs } = require('./lib-headless/xterm-headless.js');
+const termCjs = new TerminalCjs({ cols: 40, rows: 10 });
+await writeSync(termCjs, 'cjs ok');
+lineEquals(termCjs, 0, 'cjs ok');
+termCjs.dispose();
+
+console.log('headless package: ESM and CJS load, write, and buffer read OK');
diff --git a/package.json b/package.json
index 9590e8a12..d4338fc87 100644
--- a/package.json
+++ b/package.json
@@ -72,6 +72,8 @@
     "prepackage-headless": "npm run esbuild-package-headless-only",
     "package-headless": "webpack --config ./webpack.config.headless.js",
     "postpackage-headless": "node ./bin/package_headless.js",
+    "test-headless-node": "node headless/test-node-load.cjs && node headless/test-node-load.mjs",
+    "pretest-headless-node": "npm run build && npm run esbuild-package-headless-only && webpack --config ./webpack.config.headless.js",
     "prepublishOnly": "npm run package"
   },
   "devDependencies": {