autobind-decorator: "Cannot set property" error on React class component method

I’m guessing I’m missing something but not sure what.

My .babelrc:

{
  "presets": ["react", "es2015", "stage-0"],

  "plugins": [
    "transform-decorators-legacy"
  ],

  "env": {
    "development": {
      "plugins": [ "typecheck" ]
    }
  }
}

My webpack loader config:

{
    test: /\.jsx?$/,
    exclude: /node_modules/,
    loaders: [ 'react-hot', 'babel?presets[]=es2015&presets[]=react&presets[]=stage-0&plugins[]=transform-decorators-legacy' ]
}

My .eslintrc (I have no idea if both of these are needed):

  "parser": "babel-eslint",
  "settings": {
    "import/parser": "babel-eslint",

In my React component, I use the autobind decorator:

import autobind from 'autobind-decorator';

export default class Home extends Component {

    @autobind
    onPress() {}

}

But I get the runtime error:

makeAssimilatePrototype.js:21 Uncaught TypeError: Cannot set property onPress of #<Home> which has only a getter