Yeah, just hit this while updating dependencies. It started erroring before I updated from 2.9.1 to 3.1.0, though; so I don't think this is a mere regression.

Regardless, what's the intended fix here? Kinda frustrated.

Before a fix is available you can override the types like so:

useOnClickOutside<HTMLUListElement>(ref as React.RefObject<HTMLUListElement>, () => setIsOpen(false));

although, I am not endorsing it.

Im hitting the same error with useResizeObserver . Is this potentially related? I hit this error when updating to react v19.

useHover also affected. I've added a usehooks.d.ts:

import 'usehooks-ts'

  // React 19 issue: https://github.com/juliencrn/usehooks-ts/issues/663
declare module 'usehooks-ts' {
  declare function useOnClickOutside<T extends HTMLElement = HTMLElement>(
    ref: RefObject<T | null | undefined> | RefObject<T | null | undefined>[],
    handler: (event: MouseEvent | TouchEvent | FocusEvent) => void,
    eventType?: EventType,
    eventListenerOptions?: AddEventListenerOptions
  ): void

  declare function useHover<T extends HTMLElement = HTMLElement>(elementRef: RefObject<T | null | undefined>): boolean;
}

Bump on this issue. Are there any PRs to fix this?

This is because this package doesn't support React 19 (at least typings-wise). React 19 made an undocumented change to one of the useRef overloads:

- useRef<T>(initialValue: T | null): RefObject<T>
+ useRef<T>(initialValue: T | null): RefObject<T | null>

A PR that fixes these issues would just be one that updates the package to React 19, and then resolves all the type issues

Nvm there are 2 separate pull requests already that fix this, but maintainer doesn't seem to be around. If you're looking for a replacement, @mantine/hooks is pretty good. Even uses animation frames for their useResizeObserver