# What changed in @lit/reactive-element

> 8 changes in @lit/reactive-element 2 from its official release notes, upgrade guides and advisories: 3 breaking, 1 deprecations. Each one cited. Sources checked 2026-10-27. HTML: https://unstale.sh/npm/@lit/reactive-element/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## @lit/reactive-element 2

### Breaking changes

- Internet Explorer 11 is no longer supported. (2.0.0) — [release notes](https://github.com/lit/lit/releases/tag/%40lit/reactive-element%402.0.0)
- The deprecated behavior and arguments were deleted; migrate selector usage to @queryAssignedElements. (2.0.0) — [release notes](https://github.com/lit/lit/releases/tag/%40lit/reactive-element%402.0.0)
- Generated accessors now wrap user accessors and automatically call this.requestUpdate() in the setter; with noAccessor: true, users must call this.requestUpdate() themselves to trigger an update. (2.0.0) — [release notes](https://github.com/lit/lit/releases/tag/%40lit/reactive-element%402.0.0)

### Deprecations

- Async overrides of performUpdate() now produce a warning. (2.0.0) — [release notes](https://github.com/lit/lit/releases/tag/%40lit/reactive-element%402.0.0)

### Fixes and other changes

- Decorators now work with the accessor keyword when experimentalDecorators is true. (2.0.0) — [release notes](https://github.com/lit/lit/releases/tag/%40lit/reactive-element%402.0.0)
- The return type now includes undefined. (2.0.0) — [release notes](https://github.com/lit/lit/releases/tag/%40lit/reactive-element%402.0.0)
- The return type is now HTMLElement | DocumentFragment, matching renderRoot and lit-html's render() method. (2.0.0) — [release notes](https://github.com/lit/lit/releases/tag/%40lit/reactive-element%402.0.0)
- The type is now HTMLElement | DocumentFragment, matching createRenderRoot() and lit-html's render() method. (2.0.0) — [release notes](https://github.com/lit/lit/releases/tag/%40lit/reactive-element%402.0.0)