diff --git a/guides/source/active_storage_overview.md b/guides/source/active_storage_overview.md
index e67cfbed8c..2c1db74c12 100644
--- a/guides/source/active_storage_overview.md
+++ b/guides/source/active_storage_overview.md
@@ -291,6 +291,8 @@ public_gcs:
 
 Make sure your buckets are properly configured for public access. See docs on how to enable public read permissions for [Amazon S3](https://docs.aws.amazon.com/AmazonS3/latest/user-guide/block-public-access-bucket.html), [Google Cloud Storage](https://cloud.google.com/storage/docs/access-control/making-data-public#buckets), and [Microsoft Azure](https://docs.microsoft.com/en-us/azure/storage/blobs/storage-manage-access-to-resources#set-container-public-access-level-in-the-azure-portal) storage services.
 
+When converting an existing application to use `public: true`, make sure to update every individual file in the bucket to be publicly-readable before switching over.
+
 Attaching Files to Records
 --------------------------