diff --git a/lib/find-license.js b/lib/find-license.js
index a34c141..eb34de0 100644
--- a/lib/find-license.js
+++ b/lib/find-license.js
@@ -1,10 +1,12 @@
-import {promises as fs} from 'node:fs'
+import fs from 'node:fs/promises'
 
 const licenseRegexp = /^licen[cs]e(?=$|\.)/i
 
 /**
  * @param {string} base
- * @returns {Promise<string|undefined>}
+ *   Folder.
+ * @returns {Promise<string | undefined>}
+ *   Basename of license file.
  */
 export async function findLicense(base) {
   const files = await fs.readdir(base)
diff --git a/lib/find-nearest-package.js b/lib/find-nearest-package.js
index 2728409..14f06ef 100644
--- a/lib/find-nearest-package.js
+++ b/lib/find-nearest-package.js
@@ -1,25 +1,49 @@
+/**
+ * @typedef {import('vfile').VFile} VFile
+ */
+
+/**
+ * @typedef Info
+ *   Info.
+ * @property {string} folder
+ *   Path to folder with `package.json`.
+ * @property {string | undefined} license
+ *   SPDX identifier.
+ * @property {string | undefined} name
+ *   Name of author.
+ * @property {string | undefined} url
+ *   URL for author.
+ */
+
+import fs from 'node:fs/promises'
+import path from 'node:path'
 import parse from 'parse-author'
-import {read} from 'to-vfile'
 import {findUp} from 'vfile-find-up'
 
 /**
- * @param {string} base
- * @returns {Promise<{license: string|undefined, name: string|undefined, url: string|undefined}>}
+ * @param {VFile} from
+ *   File to resolve from.
+ * @returns {Promise<Info | undefined>}
+ *   Info.
  */
-export async function findNearestPackage(base) {
+export async function findNearestPackage(from) {
+  /* c8 ignore next -- else is for stdin, typically not used. */
+  const base = from.dirname ? path.resolve(from.cwd, from.dirname) : from.cwd
   const file = await findUp('package.json', base)
 
   if (file) {
-    await read(file)
+    file.value = await fs.readFile(file.path)
     /** @type {import('type-fest').PackageJson} */
     const json = JSON.parse(String(file))
     const author =
       typeof json.author === 'string' ? parse(json.author) : json.author || {}
 
-    return {license: json.license, name: author.name, url: author.url}
+    return {
+      /* c8 ignore next -- always defined. */
+      folder: file.dirname ? path.resolve(file.cwd, file.dirname) : file.cwd,
+      license: json.license,
+      name: author.name,
+      url: author.url
+    }
   }
-
-  // V8 bug on Node 12.
-  /* c8 ignore next 2 */
-  return {license: undefined, name: undefined, url: undefined}
 }
diff --git a/lib/index.js b/lib/index.js
index cede4f3..d08f1cf 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -1,102 +1,89 @@
 /**
- * @typedef {import('mdast').Root} Root
- * @typedef {import('mdast').Paragraph} Paragraph
  * @typedef {import('mdast').Link} Link
+ * @typedef {import('mdast').Paragraph} Paragraph
  * @typedef {import('mdast').PhrasingContent} PhrasingContent
+ * @typedef {import('mdast').Root} Root
  *
+ * @typedef {import('vfile').VFile} VFile
+ */
+
+/**
  * @typedef Options
  *   Configuration (optional).
- * @property {string} [name]
- *   License holder.
- *   Detected from the `package.json` closest to the file supporting both
- *   `object` and `string` format of `author`.
- *   *Throws when neither given nor detected.*
- * @property {string} [license]
- *   SPDX identifier
- *   Detected from the `license` field in the `package.json` in the current
- *   working directory.
- *   Deprecated license objects are not supported.
- *   *Throws when neither given nor detected.*
- * @property {string} [file]
- *   File name of license file
- *   Detected from the files in the directory of the `package.json` if there is
+ * @property {boolean | null | undefined} [ignoreFinalDefinitions=true]
+ *   Ignore definitions at the end of the license section (default: `true`).
+ * @property {string | null | undefined} [file]
+ *   Path to license file (optional);
+ *   detected from the files in the directory of the `package.json` if there is
  *   one, or the current working directory, in which case the first file
- *   matching `/^licen[cs]e(?=$|\.)/i` is used.
- *   If there is no given or found license file, but `options.license` is a
+ *   matching `/^licen[cs]e(?=$|\.)/i` is used;
+ *   if there is no given or found license file, but `options.license` is a
  *   known SPDX identifier, the URL to the license on `spdx.org` is used.
- * @property {string} [url]
- *   URL to license holder
- *   Detected from the `package.json` in the current working directory,
- *   supporting both `object` and `string` format of `author`.
- *   `http://` is prepended if `url` starts without HTTP or HTTPS protocol.
- * @property {boolean} [ignoreFinalDefinitions=true]
- *   Ignore final definitions otherwise in the section.
- * @property {string|RegExp} [heading]
- *   Heading to look for.
- *   Default: `/^licen[cs]e$/i`.
+ * @property {RegExp | string | null | undefined} [heading]
+ *   Heading to look for (default: `/^licen[cs]e$/i`).
+ * @property {string | null | undefined} [license]
+ *   SPDX identifier (optional, example: `'mit'`);
+ *   detected from the `license` field in the `package.json` in the current
+ *   working directory;
+ *   throws when neither given nor detected.
+ * @property {string | null | undefined} [name]
+ *   License holder (optional);
+ *   detected from the `package.json` closest to the file supporting both
+ *   `object` and `string` format of `author`;
+ *   throws when neither given nor detected.
+ * @property {string | null | undefined} [url]
+ *   URL to license holder (optional);
+ *   detected from the `package.json` in the current working directory.
  */
 
-import path from 'node:path'
-import spdx from 'spdx-license-list'
-import {findUp} from 'vfile-find-up'
 import {headingRange} from 'mdast-util-heading-range'
+import spdx from 'spdx-license-list'
 import {findNearestPackage} from './find-nearest-package.js'
 import {findLicense} from './find-license.js'
 
-const licenseHeadingRegexp = /^licen[cs]e$/i
 const http = 'http://'
 const https = 'https://'
+const licenseHeadingRegexp = /^licen[cs]e$/i
+
+/** @type {Readonly<Options>} */
+const emptyOptions = {}
 
 /**
- * Plugin to generate a license section.
+ * Generate a license section.
  *
- * @type {import('unified').Plugin<[Options], Root>}
+ * @param {Readonly<Options> | null | undefined} [options]
+ *   Configuration (optional).
+ * @returns
+ *   Transform.
  */
-export default function remarkLicense(options = {}) {
-  const ignoreFinalDefinitions =
-    options.ignoreFinalDefinitions === undefined ||
-    options.ignoreFinalDefinitions === null
-      ? true
-      : options.ignoreFinalDefinitions
-  const test = options.heading || licenseHeadingRegexp
-
+export default function remarkLicense(options) {
+  const settings = options || emptyOptions
+  const ignoreFinalDefinitions = settings.ignoreFinalDefinitions !== false
+  const test = settings.heading || licenseHeadingRegexp
+
+  /**
+   * Transform.
+   *
+   * @param {Root} tree
+   *   Tree.
+   * @param {VFile} file
+   *   File.
+   * @returns {Promise<undefined>}
+   *   Nothing.
+   */
   return async function (tree, file) {
-    // Else is for stdin, typically not used.
-    /* c8 ignore next */
-    const base = file.dirname ? path.resolve(file.cwd, file.dirname) : file.cwd
-    const packageFile = await findUp('package.json', base)
-    /** @type {string|undefined} */
-    let defaultName
-    /** @type {string|undefined} */
-    let defaultUrl
-    /** @type {string|undefined} */
-    let defaultLicense
-    /** @type {string|undefined} */
-    let defaultLicenseFile
-
-    // Skip package loading if we have all info in `options`.
-    if (!options.url || !options.name || !options.license) {
-      const result = await findNearestPackage(base)
-      defaultLicense = result.license
-      defaultName = result.name
-      defaultUrl = result.url
-    }
-
-    if (!options.file) {
-      defaultLicenseFile = await findLicense(
-        (packageFile &&
-          packageFile.dirname &&
-          path.resolve(packageFile.cwd, packageFile.dirname)) ||
-          file.cwd
-      )
-    }
-
-    const url = options.url || defaultUrl
-    const name = options.name || defaultName
-    const license = options.license || defaultLicense
-    let licenseFile = options.file || defaultLicenseFile
-
-    /* Ignore the license file itself. */
+    const info =
+      !settings.url || !settings.name || !settings.license || !settings.file
+        ? await findNearestPackage(file)
+        : undefined
+    const url = settings.url || (info ? info.url : undefined)
+    const name = settings.name || (info ? info.name : undefined)
+    const license = settings.license || (info ? info.license : undefined)
+    let licenseFile =
+      settings.file ||
+      (await findLicense((info ? info.folder : undefined) || file.cwd))
+
+    // Ignore the license file itself.
     if (licenseFile && file.path === licenseFile) {
       return
     }
@@ -125,11 +112,11 @@ export default function remarkLicense(options = {}) {
       tree,
       {ignoreFinalDefinitions, test},
       function (start, _, end) {
-        /** @type {PhrasingContent[]} */
+        /** @type {Array<PhrasingContent>} */
         const children = []
         /** @type {Paragraph} */
         const node = {type: 'paragraph', children}
-        /** @type {Paragraph|Link} */
+        /** @type {Link | Paragraph} */
         let parent
 
         if (licenseFile) {
diff --git a/package.json b/package.json
index e10f25c..e809da5 100644
--- a/package.json
+++ b/package.json
@@ -46,8 +46,7 @@
     "mdast-util-heading-range": "^4.0.0",
     "parse-author": "^2.0.0",
     "spdx-license-list": "^6.0.0",
-    "to-vfile": "^8.0.0",
-    "unified": "^11.0.0",
+    "vfile": "^6.0.0",
     "vfile-find-up": "^7.0.0"
   },
   "devDependencies": {
diff --git a/test/index.js b/test/index.js
index 6a6db48..43782c0 100644
--- a/test/index.js
+++ b/test/index.js
@@ -11,6 +11,14 @@ import {remark} from 'remark'
 import semver from 'semver'
 import license from '../index.js'
 
+test('remark-license', async function (t) {
+  await t.test('should expose the public api', async function () {
+    assert.deepEqual(Object.keys(await import('../index.js')).sort(), [
+      'default'
+    ])
+  })
+})
+
 test('fixtures', async function (t) {
   // Prepapre.
   const root = new URL('fixtures/', import.meta.url)
@@ -62,7 +70,6 @@ test('fixtures', async function (t) {
 
       try {
         const file = await remark()
-          // @ts-expect-error: to do: remove after update.
           .use(license, config)
           .process({
             value: await fs.readFile(inputUrl),