What minimal example or steps are needed to reproduce the bug?

• package.json

  {
    "name": "testcase",
    "version": "1.0.0",
    "type": "module",
    "dependencies": {
      "@types/node": "25.3.5",
      "stylelint": "17.4.0",
      "typescript": "5.9.3"
    }
  }

• index.ts

  import stylelint from "stylelint";

1. npm install
2. npx tsc --module nodenext --strict index.ts

What minimal configuration is needed to reproduce the bug?

Not Applicable.

How did you run Stylelint?

Not Applicable.

Which Stylelint-related dependencies are you using?

None.

What did you expect to happen?

No error.

What actually happened?

node_modules/stylelint/types/stylelint/index.d.ts:4:44 - error TS7016: Could not find a declaration file for module 'css-tree'. '/home/regseb/testcase/node_modules/css-tree/cjs/index.cjs' implicitly has an 'any' type.
  Try `npm i --save-dev @types/css-tree` if it exists or add a new declaration (.d.ts) file containing `declare module 'css-tree';`

4 import type { Lexer as CSSTreeLexer } from 'css-tree';
                                             ~~~~~~~~~~


Found 1 error in node_modules/stylelint/types/stylelint/index.d.ts:4

Do you have a proposal to fix the bug?

Add @types/css-tree in dependencies.

The bug has been present since version 17.3.0. Maybe the PR Refactor CSSTree lexer creation #9067