"Binding static in strict mode"

[chpio]

hi,

SyntaxError: .../node_modules/express/lib/express.js: Binding static in strict mode (120:11)
  118 | 
  119 | export default express;
> 120 | export var static = express.static;
      |            ^
  121 | export var query = express.query;
  122 | export var Router = express.Router;
  123 | export var Route = express.Route;

my build script:

    const plugins = [
        'external-helpers-2',
        'transform-async-to-generator',
        'transform-function-bind',
    ];

    const presets = ['es2015-rollup'];

    const bundle = await rollup({
        entry: './src/index.js',
        plugins: [
            rollupNpm({jsnext: true, main: true}),
            rollupCjs(),
            rollupBabel({
                babelrc: false,
                presets,
                plugins,
            }),
        ],
    });

    await bundle.write({
        format: 'es5',
        dest: `./index.js`,
        sourceMap: 'inline',
    });

i think, rollup cjs produces illegal code (es2015 modules with "use strict"), this causes babel to throw an error.