diff --git a/README.md b/README.md
index 2ae7c5ade86..1f338a3ebf6 100644
--- a/README.md
+++ b/README.md
@@ -106,7 +106,7 @@ To test the changes on a mobile or virtual machine, you will need to open the so
 
 1.  Run `yarn dev`
 1.  Make sure your virtual machine and mobile device are on the same network
-1.  Open http://YOUR_IP_ADDRESS:ASSIGNED_PORT/iframe.html?selectedKind=Playground&selectedStory=Playground in your mobile device or virtual machine
+1.  Open http://YOUR_IP_ADDRESS:ASSIGNED_PORT/iframe.html?path=/story/playground-playground--playground in your mobile device or virtual machine
 
 ### Testing in a consuming project
 
diff --git a/UNRELEASED.md b/UNRELEASED.md
index 91116146ec0..ae242302589 100644
--- a/UNRELEASED.md
+++ b/UNRELEASED.md
@@ -28,6 +28,8 @@ Use [the changelog guidelines](https://git.io/polaris-changelog-guidelines) to f
 
 ### Documentation
 
+- Fixed incorrect url for tophatting the `Playground` component inside an iframe ([4392](https://github.com/Shopify/polaris-react/pull/4392))
+
 ### Development workflow
 
 ### Dependency upgrades