diff --git a/assets/js/swagger.yml b/assets/js/swagger.yml
index e6eb6e905..0c59b35be 100644
--- a/assets/js/swagger.yml
+++ b/assets/js/swagger.yml
@@ -1369,6 +1369,10 @@ components:
         content_type:
           type: string
           description: Object media type
+        mtime:
+          type: integer
+          format: int64
+          description: Unix Epoch in seconds.  May be ignored by server.
         force:
           type: boolean
           default: false