diff --git a/docs/config/pool.md b/docs/config/pool.md
index 1980e84ca..8c6a37dec 100644
--- a/docs/config/pool.md
+++ b/docs/config/pool.md
@@ -47,6 +47,17 @@ catch (err) {
 }
 ```
 
+- Objects and arrays created by Node.js APIs and by the test environment come from outside of the sandbox too. This includes the result of `await response.json()` on a `Response` or a `Request`, `structuredClone()`, `path.parse()` and DOM methods like `element.getAttributeNames()`. Their prototype is not the `Object.prototype` or `Array.prototype` of your tests, so [`toStrictEqual`](/api/expect#tostrictequal) does not consider them equal to the same literal, and libraries that detect plain objects by their prototype treat them as class instances. If your tests depend on these values, run them in the `forks` or `threads` pool, or parse fetch responses inside the sandbox in a [setup file](/config/setupfiles):
+
+```ts [vitest.setup.ts]
+Response.prototype.json = async function () {
+  return JSON.parse(await this.text())
+}
+Request.prototype.json = async function () {
+  return JSON.parse(await this.text())
+}
+```
+
 - Importing ES modules caches them indefinitely which introduces memory leaks if you have a lot of contexts (test files). There is no API in Node.js that clears that cache.
 - Accessing globals [takes longer](https://github.com/nodejs/node/issues/31658) in a sandbox environment.