# Source: https://developers.raycast.com/misc/migration/v1.51.0.md

# v1.51.0

This version changed `environment.theme` to `environment.appearance`.

{% hint style="info" %}
`environment.theme` still works, but is now marked as deprecated and may be removed in a future version. You will get helpful hints in your code editor to migrate your extension, and as usual we provide automated [migrations](https://developers.raycast.com/misc/migration) to help with the transition.
{% endhint %}

To migrate your extension manually, you need to ensure that all `environment.theme` are updated to `environment.appearance`.