diff --git a/docs/design/proposals/rbd-mirror.md b/docs/design/proposals/rbd-mirror.md
index bc2a41311..7d0e5c09d 100644
--- a/docs/design/proposals/rbd-mirror.md
+++ b/docs/design/proposals/rbd-mirror.md
@@ -47,7 +47,6 @@ csi:
   volumeAttributes:
     clusterID: rook-ceph
     imageFeatures: layering
-    imageFormat: "2"
     imageName: csi-vol-0c23de1c-18fb-11eb-a903-0242ac110005
     journalPool: replicapool
     pool: replicapool