ThemeProvider returns multiple types

[javi95z]

Type error: 'ThemeProvider' cannot be used as a JSX component. 
Its return type 'string | number | boolean | Iterable<ReactNode> | Element' is not a valid JSX element.

[TomTom-Labs]

For me, the problem was introduced: next-themes ^0.2.1 → ^0.3.0

Type error: 'ThemeProvider' cannot be used as a JSX component.
  Its return type 'string | number | boolean | Element | Iterable<ReactNode>' is not a valid JSX element.
    Type 'string' is not assignable to type 'ReactElement<any, any>'.

[trm217]

@javi95z We need more information if we are to look into this. Can you please provide a reproduction?
(Context: I have ~10 Next.js Apps on v14 with next-themes v0.3 running without any such issues)

[vshakun]

Hello!

I have the same issue using

{
  "next-themes": "^0.3.0",
  "react": "^18.2.0", 
  "vite": "^5.2.8"
}

Downgrading next-themes to ^0.2.1 fixes the issue.