---
title: Mergify Update Command
description: Update a pull request by merging its base branch into it.
---

The `update` command keeps pull requests current with their base branch. When
the base branch sees frequent changes, it's not uncommon for pull requests to
become outdated.

Instead of manually merging the base branch, you can let the `update` command
take care of it.

## Syntax

```text
@Mergifyio update
```

## Fork Pull Requests

`update` merges the base branch into the pull request rather than rewriting its
head branch, and it impersonates nobody unless you configure a
[`bot_account`](/configuration/data-types#bot-account). Use it on pull requests
opened from a fork, where [`rebase`](/commands/rebase) is deprecated.

The merge commit still lands on the pull request's head branch, which on a fork
belongs to the author's repository. When the base repository is public, the
author has to have allowed maintainers to modify that branch; without it, the
command reports that Mergify needs the author's permission to update the
branch, and only the author can unblock it, by enabling the setting or updating
the branch themselves. GitHub documents it under [allowing changes to a pull
request branch created from a fork][gh-fork-edits].

[gh-fork-edits]: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/allowing-changes-to-a-pull-request-branch-created-from-a-fork