diff --git a/contributing/core/testing.md b/contributing/core/testing.md
index 0b59624830..a59def7cec 100644
--- a/contributing/core/testing.md
+++ b/contributing/core/testing.md
@@ -130,17 +130,29 @@ TURBOPACK=1 pnpm test-dev test/e2e/app-dir/app/
 
 Every branch build will create a tarball for each package in this repository<sup>1</sup> that can be used in external repositories.
 
-You can use this preview build in other packages by using a https://vercel-packages.vercel.app URL instead of a version in the `package.json` e.g.
+You can use this preview build in other packages by using a https://vercel-packages.vercel.app URL instead of a version in the `package.json`.
+Dependencies are automatically rewritten to use the same commit SHA as the package you are using.
+For example, if you install `next` from commit `abc`, `next` will have a dependency on `@next/env` at commit `abc` **and** use `next-swc` from commit `abc` as well.
+
+To use `next` from a specific commit (full SHA required):
 
 ```json
 {
   "dependencies": {
-    "next": "https://vercel-packages.vercel.app/next/commits/abcd/next"
+    "next": "https://vercel-packages.vercel.app/next/commits/188f76947389a27e9bcff8ebf9079433679256a7/next"
   }
 }
 ```
 
-You can refer to builds only by commit SHAs at the moment.
+or, to use `next` from a specific Pull Request (PR number required):
+
+```json
+{
+  "dependencies": {
+    "next": "https://vercel-packages.vercel.app/next/prs/66445/next"
+  }
+}
+```
 
 <sup>1</sup> Not all native packages are built automatically.
 `build-and-deploy` excludes slow, rarely used native variants of `next-swc`.