Disable babel's escaping of characters in stringLiteral

Question

It seems babel is doing some automatic escaping of special characters when using t.stringLiteral which causes problems for me. Is there any way to disable this behaviour or a workaround perhaps?

stringBabelPlugin.js

const t = require("@babel/types")

module.exports = ({ types: t }) => {
    return {
        visitor: {
            CallExpression: {
                exit(path, state) {
                    path.replaceWith(t.stringLiteral('ö'))
                },
            },
        }
    }
}

stringBabelPlugin.spec.js

import { pluginTester } from 'babel-plugin-tester';
import stringPlugin from './stringPlugin';


pluginTester({
  plugin: stringPlugin,
  tests: [
    {
      code: `fn("ö")`,
      output: `"ö"`,
    },
  ],
});

npm test

  - Expected   ""ö""
  + Received   ""\xF6";"

Github repo to reproduce