babel: Can't find private variable @derivedConstructor (Safari iOS 10.3.1)

Bug Report

Current Behavior

Can't find private variable @derivedConstructor error on Safari iOS 10.3.1

Input Code

The following code generated an error on Safari iOS 10.3.1:

before Babel:

someFunction = async () => {
  ...
}

after Babel:

_defineProperty(this, "someFunction", async (props, state) => {
  ...
}

Expected behavior/code

The example is working on Safari iOS 10.0 and Safari iOS 11

Babel Configuration (.babelrc, package.json, cli command)

const pkg = require('./package.json');

module.exports = api => {
  const env = api.env();

  const presets = [
    [
      '@babel/env',
      {
        modules: false,
        useBuiltIns: 'entry',
        { targets: { esmodules: true },
      },
    ],
    '@babel/react',
    '@babel/typescript',
  ];

  const plugins = [
    '@babel/proposal-class-properties',
    '@babel/plugin-syntax-dynamic-import',
  ].filter(Boolean);

  return {
    presets,
    plugins,
  };
};

Environment

• Babel version(s): Latest for all babel-related packages:

    "@babel/core": "7.2.2",
    "@babel/plugin-proposal-class-properties": "7.2.3",
    "@babel/plugin-syntax-dynamic-import": "7.2.0",
    "@babel/plugin-transform-react-jsx-source": "7.2.0",
    "@babel/preset-env": "7.2.3",
    "@babel/preset-react": "7.0.0",
    "@babel/preset-typescript": "7.1.0",

• Node/npm version: Node 10.15.0 / Yarn 1.13.0
• OS: Mac OSX 10.14.2
• Monorepo: yes
• How you are using Babel: loader via webpack

Possible Solution

Additional context/Screenshots

Please let me know if I can help in any way!