diff --git a/lib/index.js b/lib/index.js
index 3731210..80b2434 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -1,24 +1,35 @@
 /**
  * @typedef {import('hast').Root} Root
  * @typedef {import('hast-util-raw').Options} RawOptions
- * @typedef {import('hast-util-raw')} DoNotTouchAsThisImportIncludesRawInTree
+ * @typedef {import('vfile').VFile} VFile
  */
 
 /**
  * @typedef {Omit<RawOptions, 'file'>} Options
+ *   Configuration.
  */
 
 import {raw} from 'hast-util-raw'
 
 /**
- * Plugin to parse the tree again (and raw nodes).
- * Keeping positional info OK.  🙌
+ * Parse the tree (and raw nodes) again, keeping positional info okay.
  *
- * @type {import('unified').Plugin<[Options?] | Array<void>, Root>}
+ * @param {Options | null | undefined}  [options]
+ *   Configuration (optional).
+ * @returns
+ *   Transform.
  */
-export default function rehypeRaw(options = {}) {
-  return (tree, file) => {
-    // Assume that when a root was given, it’s also returned.
+export default function rehypeRaw(options) {
+  /**
+   * @param {Root} tree
+   *   Tree.
+   * @param {VFile} file
+   *   File.
+   * @returns {Root}
+   *   New tree.
+   */
+  return function (tree, file) {
+    // Assume root in -> root out.
     const result = /** @type {Root} */ (raw(tree, {...options, file}))
     return result
   }
diff --git a/package.json b/package.json
index 029db3e..817b2fb 100644
--- a/package.json
+++ b/package.json
@@ -33,7 +33,7 @@
   "dependencies": {
     "@types/hast": "^3.0.0",
     "hast-util-raw": "^9.0.0",
-    "unified": "^11.0.0"
+    "vfile": "^6.0.0"
   },
   "devDependencies": {
     "@types/node": "^20.0.0",
@@ -46,6 +46,7 @@
     "remark-rehype": "^10.0.0",
     "type-coverage": "^2.0.0",
     "typescript": "^5.0.0",
+    "unified": "^11.0.0",
     "unist-util-visit": "^5.0.0",
     "xo": "^0.56.0"
   },
diff --git a/test.js b/test.js
index fcdadd0..081f6d4 100644
--- a/test.js
+++ b/test.js
@@ -2,42 +2,50 @@
  * @typedef {import('hast').Root} Root
  */
 
-import test from 'node:test'
 import assert from 'node:assert/strict'
-import {unified} from 'unified'
-import {visit} from 'unist-util-visit'
+import test from 'node:test'
+import rehypeStringify from 'rehype-stringify'
 import remarkParse from 'remark-parse'
 import remarkRehype from 'remark-rehype'
-import rehypeStringify from 'rehype-stringify'
+import {unified} from 'unified'
+import {visit} from 'unist-util-visit'
 import rehypeRaw from './index.js'
 
-const markdown = `<div class="note">
+test('rehypeRaw', async function (t) {
+  await t.test('should expose the public api', async function () {
+    assert.deepEqual(Object.keys(await import('./index.js')).sort(), [
+      'default'
+    ])
+  })
+
+  await t.test('should work', async function () {
+    const file = await unified()
+      // @ts-expect-error: to do: remove when remark is released.
+      .use(remarkParse)
+      // @ts-expect-error: to do: remove when remark-rehype is released.
+      .use(remarkRehype, {allowDangerousHtml: true})
+      .use(rehypeRaw)
+      .use(function () {
+        /**
+         * @param {Root} root
+         */
+        return function (root) {
+          visit(root, 'raw', function () {
+            assert.fail()
+          })
+        }
+      })
+      .use(rehypeStringify).process(`<div class="note">
 
 A mix of *markdown* and <em>HTML</em>.
 
-</div>`
+</div>`)
 
-const html = `<div class="note">
+    assert.equal(
+      String(file),
+      `<div class="note">
 <p>A mix of <em>markdown</em> and <em>HTML</em>.</p>
 </div>`
-
-test('rehypeRaw', async () => {
-  const file = await unified()
-    // @ts-expect-error: to do: remove when remark is released.
-    .use(remarkParse)
-    // @ts-expect-error: to do: remove when remark-rehype is released.
-    .use(remarkRehype, {allowDangerousHtml: true})
-    .use(rehypeRaw)
-    .use(
-      /** @type {import('unified').Plugin<Array<void>, Root>} */
-      () => (root) => {
-        visit(root, 'raw', () => {
-          assert.fail('should not include `raw` in tree after `rehype-raw`')
-        })
-      }
     )
-    .use(rehypeStringify)
-    .process(markdown)
-
-  assert.equal(String(file), html, 'should equal the fixture')
+  })
 })