---
title: "Sound Typing for 'this' in Flow"
short-title: "Sound Typing for 'this'"
authors: [daniel-sainati]
medium-link: "https://medium.com/flow-type/sound-typing-for-this-in-flow-d62db2af969e"
---

:::info[Historical]
This post announced sound typing for `this` when it was introduced. For current syntax and behavior, see the [Functions](/en/docs/types/functions) documentation.
:::

Improvements in soundness for `this`-typing in Flow, including the ability to annotate `this` on functions and methods.
