es6 module testing with babel tape runner ????

babel-tape-runner

// add.js

export default function (a, b) {
  return a + b
}

// test.js

var test = require('tape');
import add from './add';

test('This is a thing!', function (t) {
  t.plan(1);
  var result = add(1,1)
  var expect = 2
  t.equal(result, expect, 'This fails.');
});

// cli
$ babel-tape-runner tests/app/test.js | tap-spec

ERR-OR!:

var _add2 = babelHelpers.interopRequireDefault(_add);
            ^

ReferenceError: babelHelpers is not defined