To reproduce the bug:

pnpm install
dts-bundle-generator index.d.ts --out-file bundled.d.ts

Output is

Compiling input files...
Processing index.d.ts
Writing index.d.ts -> bundled.d.ts
Checking generated files...
bundled.d.ts(7,15): error TS2503: Cannot find namespace 'i0'.
bundled.d.ts(8,15): error TS2503: Cannot find namespace 'i0'.
bundled.d.ts(9,15): error TS2503: Cannot find namespace 'i0'.

Error: Failed to check some of generated bundles, check error messages above

This worked in previous dts-bundle-generator (9.3.1) but not in new ones (9.4.0 / 9.5.0)