# TS2717: Subsequent property declarations must have the same type.  Property '…' must be of type '…', but here has type '…'.

> A property is declared again (in a merged interface or declaration) with a different type. Give every declaration the same type.

## What it means

When interfaces or other declarations merge, a property that appears in more than one of them must
have the identical type each time.

## Example

```ts
interface Options { timeout: number }
interface Options { timeout: string }
export {};
```

## How to fix

- Make every declaration of the property use the same type.
- If the property needs to accept both, declare it once with a union type.

Source: https://ts-r.dev/errors/TS2717/