diff --git a/xero_accounting.yaml b/xero_accounting.yaml
index ab299e5ae..02a1bdf3d 100644
--- a/xero_accounting.yaml
+++ b/xero_accounting.yaml
@@ -10776,7 +10776,7 @@ paths:
             application/octet-stream:
               schema:
                 type: string
-                format: byte
+                format: binary
   /ManualJournals/{ManualJournalID}/Attachments/{FileName}:
     parameters:
       - $ref: '#/components/parameters/requiredHeader'