diff --git a/buds/02.md b/buds/02.md
index 7264be9..e491892 100644
--- a/buds/02.md
+++ b/buds/02.md
@@ -15,7 +15,7 @@ A blob descriptor is a JSON object containing `url`, `sha256`, `size`, `type`, a
 - `url` A publicly accessible URL to the [BUD-01](./01.md#get-sha256---get-blob) `GET /<sha256>` endpoint with a file extension
 - `sha256` The sha256 hash of the blob
 - `size` The size of the blob in bytes
-- `type` (optional) The MIME type of the blob
+- `type` The MIME type of the blob (falling back to `application/octet-stream` if unknown)
 - `uploaded` The unix timestamp of when the blob was uploaded to the server
 
 Servers MUST include a file extension in the URL in the `url` field to allow clients to easily embed the URL in social posts or other content