# source_case_mismatch

> An import's case differs from the file name on disk.

An import's case differs from the file name on disk.

| | |
| --- | --- |
| Kind | Build or validation problem |
| Reported by | The build (source walk and TypeScript), before any archive exists |
| `disko` exit code | 1 (problems) |

An import's case differs from the file name on disk. Imports must match the
file name exactly, and the build checks this even on case-insensitive file
systems such as the macOS and Windows defaults, so the game behaves the same
everywhere.

## Wrong

```ts title="src/main.ts"
// The file is src/rules.ts.
import { scoreGoal } from "./Rules.ts";
```

## Right

```ts title="src/main.ts"
import { scoreGoal } from "./rules.ts";
```

## See also

- [Project structure & imports](/games/project-structure)
- [`source_file_missing`](/errors/source_file_missing)