diff --git a/controller/types/types.go b/controller/types/types.go
index <HASH>..<HASH> 100644
--- a/controller/types/types.go
+++ b/controller/types/types.go
@@ -28,6 +28,11 @@ type ExpandedFormation struct {
 	Tags      map[string]map[string]string `json:"tags,omitempty"`
 	UpdatedAt time.Time                    `json:"updated_at,omitempty"`
 	Deleted   bool                         `json:"deleted,omitempty"`
+
+	// DeprecatedImageArtifact is for creating backwards compatible cluster
+	// backups (the restore process used to require the ImageArtifact field
+	// to be set).
+	DeprecatedImageArtifact *Artifact `json:"artifact,omitempty"`
 }
 
 type App struct {
diff --git a/pkg/backup/backup.go b/pkg/backup/backup.go
index <HASH>..<HASH> 100644
--- a/pkg/backup/backup.go
+++ b/pkg/backup/backup.go
@@ -115,6 +115,11 @@ func getApps(client controller.Client) (map[string]*ct.ExpandedFormation, error)
 			App:       app,
 			Release:   release,
 			Processes: formation.Processes,
+
+			// set DeprecatedImageArtifact to support restoring
+			// to old clusters (the URI is overwritten on restore,
+			// but the field is expected to be set)
+			DeprecatedImageArtifact: &ct.Artifact{Type: ct.DeprecatedArtifactTypeDocker},
 		}
 	}
 	return data, nil
pkg/backup: Create backwards compatible backups