---
title: Fix Astro 7 markdown.rehypePlugins Deprecation Warning
description: Fix Astro 7's markdown.rehypePlugins deprecation warning. The exact config fix, tested live against a real Astro 7 build.
date: 2026-08-05T00:00:00.000Z
category: guides-fixes
tags: astro, mdx, config, bug-fix
---

## Quick Answer

Setting `markdown.rehypePlugins` (or `remarkPlugins` / `remarkRehype`) directly in `astro.config.mjs` now prints: `[astro] markdown.remarkPlugins, markdown.rehypePlugins, and markdown.remarkRehype are deprecated. Pass them to unified({...}) from @astrojs/markdown-remark directly instead.` Wrap the same plugins inside `processor: unified({ rehypePlugins: [...] })` and the warning is gone.

## Why the warning happens

Astro 7 defaults to Sätteri, a new Rust Markdown processor with no plugin system of its own. Setting `markdown.remarkPlugins`, `markdown.rehypePlugins`, or `markdown.remarkRehype` at the top level tells Astro to fall back to the older `@astrojs/markdown-remark` unified pipeline instead, since only that pipeline can run remark and rehype plugins at all.

That fallback still works. The top-level config keys used to trigger it are deprecated, in favor of passing the same options directly to a `unified()` processor object. This site's own `astro.config.mjs` hits the warning for exactly this reason: it sets `markdown.rehypePlugins` to add `scope="col"` to table headers and to style code block chrome, both real rehype plugins this site depends on.

```bash title="npx astro build on this site's own astro@7.1.3"
[astro] `markdown.remarkPlugins`, `markdown.rehypePlugins`, and `markdown.remarkRehype` are deprecated. Pass them to `unified({...})` from `@astrojs/markdown-remark` directly instead.
```

<Callout
  type="warning"
  title="Scheduled for removal in Astro 8, not just deprecated"
>
  Astro's [6.4 release notes](https://astro.build/blog/astro-640/) list this as
  scheduled for removal in Astro 8.0. It still works fully on Astro 7, but treat
  the warning as a heads-up to migrate, not noise to ignore.
</Callout>

## The fix: move plugins into unified()

`@astrojs/markdown-remark` exports a `unified()` processor factory built exactly for this. Its own type definitions document the replacement shape directly:

```js title="astro.config.mjs - before"
// BROKEN, prints the deprecation warning on every build
markdown: {
  rehypePlugins: [rehypeTableHeaderScope, rehypeCodeBlockChrome],
},
```

```js title="astro.config.mjs - after"
import { unified } from "@astrojs/markdown-remark";

// FIXED, same plugins, no warning
markdown: {
  processor: unified({
    rehypePlugins: [rehypeTableHeaderScope, rehypeCodeBlockChrome],
  }),
},
```

`remarkPlugins` and `remarkRehype` move the same way, as options on that same `unified({...})` call.

## Confirmed against a real build

Applying this exact change to this site's own `astro.config.mjs` and running `npx astro build` removes the warning completely, with all 52 pages still building. The `scope="col"` attribute the `rehypeTableHeaderScope` plugin adds still shows up in the rendered output afterward, confirmed by grepping the built HTML for both posts that use a table. Nothing about the page output changed, only the warning disappeared.

This site hasn't made the change permanent yet since the deprecated form still works cleanly on `astro@7.1.3`, but the fix above is the exact, tested change to make when migrating ahead of Astro 8.

See the [Guides & Fixes](/guides-fixes) archive for more fixes from this same upgrade.