diff --git a/doc/book/connect/backup.md b/doc/book/connect/backup.md
index 7e97d777..8635b969 100644
--- a/doc/book/connect/backup.md
+++ b/doc/book/connect/backup.md
@@ -207,3 +207,15 @@ $ plakar at @garageS3 ls
 ```
 
 More information in Plakar documentation: https://www.plakar.io/docs/main/quickstart/
+
+## Synology HyperBackup
+
+HyperBackup can be configured upload backups to garage using a custom S3 destination. However, the HyperBackup client hardcodes the `us-east-1` region
+that is a critical input to the v4 signature process. If garage does not use `us-east-1`, HyperBackup will recognize available buckets, but fail during the
+final setup stage.
+
+In garage.toml:
+```toml
+[s3_api]
+s3_region = "us-east-1"
+```