core/CHANGELOG.txt | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/core/CHANGELOG.txt b/core/CHANGELOG.txt
index 023e135..dc96a8c 100644
--- a/core/CHANGELOG.txt
+++ b/core/CHANGELOG.txt
@@ -6,6 +6,16 @@ Versions of [Drush](https://www.drupal.org/node/2874827) earlier than 8.1.12
 will not work with Drupal 8.4.x. Update Drush to 8.1.12 before using it to
 update Drupal core or you will encounter fatal errors.
 
+## Note for sites using file uploads
+
+Certain Drupal 8 sites have been reporting vanishing files. Drupal helpfully
+removes unused files, but unfortunately there are [several file usage tracking
+bugs](https://www.drupal.org/node/2821423). To prevent further data loss,
+Drupal 8.4 has [disabled the automatic deletion of files with no remaining
+usages](https://www.drupal.org/node/2801777).
+[See the change record](https://www.drupal.org/node/2891902), which explains
+the broken scenario in detail, and describes how sites can opt out.
+
 ## New stable modules
 
 The following modules, previously considered experimental, are now stable and
@@ -54,7 +64,6 @@ for decoupled applications will be improved in a future release.
 * *[#2468045: When deleting a content type field, users do not realize the related View also is deleted](https://www.drupal.org/node/2468045)
 * *[#2542050: Toolbar implementation creates super annoying re-rendering](https://www.drupal.org/node/2542050)
 * *[#2847651: Improve timezones selector with optgroups](https://www.drupal.org/node/2847651)
-* (open) *[#2801777: Give users the option to prevent drupal from automatically marking unused files as temporary](https://www.drupal.org/node/2801777)
 * (open) *[#2846365: User roles field access is inconsistent, users with 'administer users' permission can gain full access](https://www.drupal.org/node/2846365)
 
 ## REST and API-first improvements