diff --git a/examples/with-markdown-plugins/add-classes.mjs b/examples/with-markdown-plugins/add-classes.mjs
index 54879e55d..39acabd52 100644
--- a/examples/with-markdown-plugins/add-classes.mjs
+++ b/examples/with-markdown-plugins/add-classes.mjs
@@ -1,16 +1,18 @@
 import { selectAll } from 'hast-util-select';
 
-export default additions => {
-    const adders = Object.entries(additions).map(adder);
-    return node => adders.forEach(a => a(node));
+export default (additions) => {
+	const adders = Object.entries(additions).map(adder);
+	return (node) => adders.forEach((a) => a(node));
 };
 
 const adder = ([selector, className]) => {
-    const writer = write(className);
-    return node => selectAll(selector, node).forEach(writer);
+	const writer = write(className);
+	return (node) => selectAll(selector, node).forEach(writer);
 };
 
-const write = className => ({ properties }) => {
-    if(!properties.className) properties.className = className;
-    else properties.className += ` ${className}`;
-};
+const write =
+	(className) =>
+	({ properties }) => {
+		if (!properties.className) properties.className = className;
+		else properties.className += ` ${className}`;
+	};
diff --git a/packages/astro/test/astro-markdown-plugins.test.js b/packages/astro/test/astro-markdown-plugins.test.js
index d412be897..aca9fcf7b 100644
--- a/packages/astro/test/astro-markdown-plugins.test.js
+++ b/packages/astro/test/astro-markdown-plugins.test.js
@@ -15,7 +15,11 @@ describe('Astro Markdown plugins', () => {
 					markdownRemark,
 					{
 						remarkPlugins: ['remark-code-titles', ['rehype-autolink-headings', { behavior: 'prepend' }]],
-						rehypePlugins: [[import('rehype-toc'), { headings: ['h2', 'h3'] }], [import('../../../examples/with-markdown-plugins/add-classes.mjs'), { 'h1,h2,h3': 'title' }], 'rehype-slug'],
+						rehypePlugins: [
+							[import('rehype-toc'), { headings: ['h2', 'h3'] }],
+							[import('../../../examples/with-markdown-plugins/add-classes.mjs'), { 'h1,h2,h3': 'title' }],
+							'rehype-slug',
+						],
 					},
 				],
 			},