--- sidebar_label: EventEmitter.addListener --- # EventEmitter.addListener() method > Warning: This API is now obsolete. > > please use [EventEmitter.on()](./puppeteer.eventemitter.on.md) instead. Add an event listener. **Signature:** ```typescript class EventEmitter { addListener(event: EventType, handler: Handler): EventEmitter; } ``` ## Parameters | Parameter | Type | Description | | --------- | ------------------------------------- | ----------- | | event | [EventType](./puppeteer.eventtype.md) | | | handler | [Handler](./puppeteer.handler.md) | | **Returns:** [EventEmitter](./puppeteer.eventemitter.md)