# Prerendered dynamic endpoint has path collision.

> **PrerenderDynamicEndpointPathCollide**: Could not render `PATHNAME` with an `undefined` param as the generated path will collide during prerendering. Prevent passing `undefined` as `params` for the endpoint’s `getStaticPaths()` function, or add an additional extension to the endpoint’s filename.

## What went wrong?

[Section titled “What went wrong?”](#what-went-wrong)

The endpoint is prerendered with an `undefined` param so the generated path will collide with another route.

If you cannot prevent passing `undefined`, then an additional extension can be added to the endpoint file name to generate the file with a different name. For example, renaming `pages/api/[slug].ts` to `pages/api/[slug].json.ts`.

**See Also:**

* [`getStaticPaths()`](/en/reference/routing-reference/#getstaticpaths)
* [`params`](/en/reference/api-reference/#params)