Cannot get ava transpile to work with relatively-imported files

The ES6 import works in this file, but generates an unexpected token import error when I'm importing relative files such as my Mongoose User model.

import mongoose from 'mongoose';
^^^^^^

SyntaxError: Unexpected token import

.babelrc

{
  "presets": [
    ["es2015", { "modules": false }]
  ],
  "plugins": [
    "transform-object-rest-spread",
    "transform-async-to-generator",
    "transform-export-extensions"
  ]
}

package.json

 "ava": {
    "require": [
      "babel-register"
    ]
  }

users.test.js

import test from 'ava'
import axios from 'axios'

import User from '../../models/user'
import { USER_REGISTRATION_ROUTES } from '../helpers/_test.properties.js'

test('user registration api works', async function (t) {
  const email = `test${Date.now()}@example.com`

  const userRegistrationData = {
    email,
    first_name: "john",
    last_name: "doe",
    password: "password"
  }

  await axios.post(USER_REGISTRATION_ROUTES, userRegistrationData)
    .then(response => {
      const data = response.data.data
      const user = data.user
      t.deepEqual(response.status, 200, 'Verify: response is successful')
      t.deepEqual(data.registered, true, 'Verify: user is registered')
      t.truthy(Object.keys(user).length > 0,
        'Verify: if registered, user object is returned')
      t.truthy(user.authentication_token,
        'Verify: token is generated on successful registration')
    })
    .catch((err) => {
      t.fail(`Cannot make requst to register user ${err}`)
    })

  User.remove({ email }, function (err) {
    if (err) {
      console.log('error')
    } else {
      console.log('success deleting test user')
    }
  })
})