diff --git a/registry/repository.go b/registry/repository.go
index 84a50e2a..10440608 100644
--- a/registry/repository.go
+++ b/registry/repository.go
@@ -45,6 +45,7 @@ type Repository interface {
 	content.Storage
 	content.Deleter
 	content.TagResolver
+	content.PredecessorFinder
 	ReferenceFetcher
 	ReferencePusher
 	ReferrerLister