diff --git a/internal/contentutil/reference.go b/internal/contentutil/reference.go
index 530557150..4a374b234 100644
--- a/internal/contentutil/reference.go
+++ b/internal/contentutil/reference.go
@@ -15,18 +15,10 @@ limitations under the License.
 
 package contentutil
 
-import (
-	"github.com/opencontainers/go-digest"
-	"oras.land/oras-go/v2/registry"
-)
+import "github.com/opencontainers/go-digest"
 
 // IsDigest checks if the given string is a valid digest.
 func IsDigest(tagOrDigest string) bool {
 	_, err := digest.Parse(tagOrDigest)
 	return err == nil
 }
-
-// IsValidTag checks if the given string is a valid tag.
-func IsValidTag(tag string) bool {
-	return registry.Reference{Reference: tag}.ValidateReferenceAsTag() == nil
-}
diff --git a/internal/descriptor/descriptor.go b/internal/descriptor/descriptor.go
index 46399dd3c..41f7321b7 100644
--- a/internal/descriptor/descriptor.go
+++ b/internal/descriptor/descriptor.go
@@ -22,10 +22,7 @@ import (
 )
 
 // IsManifest checks if a descriptor describes a manifest.
-<<<<<<< HEAD
 // Adapted from `oras-go`: https://github.com/oras-project/oras-go/blob/d6c837e439f4c567f8003eab6e423c22900452a8/internal/descriptor/descriptor.go#L67
-=======
->>>>>>> 704e455 (rebase)
 func IsManifest(desc ocispec.Descriptor) bool {
 	switch desc.MediaType {
 	case docker.MediaTypeManifest,