It is my understanding that in order to use pdfjs-dist from a Next application, one has to initialize the worker by hand:

// NOTE Use legacy build until Node 22
import { GlobalWorkerOptions } from 'pdfjs-dist/legacy/build/pdf';

const url = new URL('pdfjs-dist/legacy/build/pdf.worker.min.mjs', import.meta.url);
GlobalWorkerOptions.workerSrc = url.toString();

While that works fine locally, next build will error on that .mjs file with:

static/media/pdf.worker.0dfedf1d.mjs from Terser
  x 'import', and 'export' cannot be used outside of module code
       ,-[90897:1]
 90897 | const pdfjsVersion = "4.6.82";
 90898 | const pdfjsBuild = "9b541910f";
 90899 | var __webpack_exports__WorkerMessageHandler = __webpack_exports__.WorkerMessageHandler;
 90900 | export { __webpack_exports__WorkerMessageHandler as WorkerMessageHandler }; //# sourceMappingURL=pdf.worker.mjs.map
       : ^^^^^^
       `----

Caused by:
    0: failed to parse input file
    1: Syntax Error
Error: 
  x 'import', and 'export' cannot be used outside of module code
       ,-[90897:1]
 90897 | const pdfjsVersion = "4.6.82";
 90898 | const pdfjsBuild = "9b541910f";
 90899 | var __webpack_exports__WorkerMessageHandler = __webpack_exports__.WorkerMessageHandler;
 90900 | export { __webpack_exports__WorkerMessageHandler as WorkerMessageHandler }; //# sourceMappingURL=pdf.worker.mjs.map
       : ^^^^^^
       `----

Adding pdfjs-dist to transpilePackages doesn't seem to have any effect, I'm guessing because I'm not using require/import

How can I make the build comply with pdfjs-dist as MJS since this is what the library provides?