# babel-plugin-transform-es2015-parameters > Compile ES2015 default and rest parameters to ES5 This plugin transforms ES2015 parameters to ES5, this includes: - Destructuring parameters - Default parameters - Rest parameters ## Installation ```sh npm install --save-dev babel-plugin-transform-es2015-parameters ``` ## Caveats Default parameters desugar into `let` declarations to retain proper semantics. If this is not supported in your environment then you'll need the [transform-block-scoping](http://babeljs.io/docs/plugins/transform-es2015-block-scoping) plugin. ## Usage ### Via `.babelrc` (Recommended) **.babelrc** ```json { "plugins": ["transform-es2015-parameters"] } ``` ### Via CLI ```sh babel --plugins transform-es2015-parameters script.js ``` ### Via Node API ```javascript require("babel-core").transform("code", { plugins: ["transform-es2015-parameters"] }); ```