diff --git a/index.js b/index.js
index 523c5d5..dab322b 100644
--- a/index.js
+++ b/index.js
@@ -1,39 +1 @@
-/// <reference types="remark-parse" />
-/// <reference types="remark-stringify" />
-
-/**
- * @typedef {import('mdast').Root} Root
- * @typedef {import('mdast-util-directive')} DoNotTouchAsThisImportIncludesDirectivesInTree
- * @typedef {import('unified').Processor<Root>} Processor
- */
-
-import {directiveFromMarkdown, directiveToMarkdown} from 'mdast-util-directive'
-import {directive} from 'micromark-extension-directive'
-
-/**
- * Add support for generic directives.
- *
- * ###### Notes
- *
- * Doesn’t handle the directives: create your own plugin to do that.
- *
- * @returns {undefined}
- *   Nothing.
- */
-export default function remarkDirective() {
-  // @ts-expect-error: TS is wrong about `this`.
-  // eslint-disable-next-line unicorn/no-this-assignment
-  const self = /** @type {Processor} */ (this)
-  const data = self.data()
-
-  const micromarkExtensions =
-    data.micromarkExtensions || (data.micromarkExtensions = [])
-  const fromMarkdownExtensions =
-    data.fromMarkdownExtensions || (data.fromMarkdownExtensions = [])
-  const toMarkdownExtensions =
-    data.toMarkdownExtensions || (data.toMarkdownExtensions = [])
-
-  micromarkExtensions.push(directive())
-  fromMarkdownExtensions.push(directiveFromMarkdown())
-  toMarkdownExtensions.push(directiveToMarkdown())
-}
+export {default} from './lib/index.js'
diff --git a/lib/index.js b/lib/index.js
new file mode 100644
index 0000000..42a6e81
--- /dev/null
+++ b/lib/index.js
@@ -0,0 +1,39 @@
+/// <reference types="remark-parse" />
+/// <reference types="remark-stringify" />
+/// <reference types="mdast-util-directive" />
+
+/**
+ * @typedef {import('mdast').Root} Root
+ * @typedef {import('unified').Processor<Root>} Processor
+ */
+
+import {directiveFromMarkdown, directiveToMarkdown} from 'mdast-util-directive'
+import {directive} from 'micromark-extension-directive'
+
+/**
+ * Add support for generic directives.
+ *
+ * ###### Notes
+ *
+ * Doesn’t handle the directives: create your own plugin to do that.
+ *
+ * @returns {undefined}
+ *   Nothing.
+ */
+export default function remarkDirective() {
+  // @ts-expect-error: TS is wrong about `this`.
+  // eslint-disable-next-line unicorn/no-this-assignment
+  const self = /** @type {Processor} */ (this)
+  const data = self.data()
+
+  const micromarkExtensions =
+    data.micromarkExtensions || (data.micromarkExtensions = [])
+  const fromMarkdownExtensions =
+    data.fromMarkdownExtensions || (data.fromMarkdownExtensions = [])
+  const toMarkdownExtensions =
+    data.toMarkdownExtensions || (data.toMarkdownExtensions = [])
+
+  micromarkExtensions.push(directive())
+  fromMarkdownExtensions.push(directiveFromMarkdown())
+  toMarkdownExtensions.push(directiveToMarkdown())
+}
diff --git a/package.json b/package.json
index e190754..d50eaa8 100644
--- a/package.json
+++ b/package.json
@@ -29,6 +29,7 @@
   "main": "index.js",
   "types": "index.d.ts",
   "files": [
+    "lib/",
     "index.d.ts",
     "index.js"
   ],