diff --git a/cmd/oras/internal/fileref/unix.go b/cmd/oras/internal/fileref/unix.go
index d13a80fbd..fac7f378c 100644
--- a/cmd/oras/internal/fileref/unix.go
+++ b/cmd/oras/internal/fileref/unix.go
@@ -23,7 +23,9 @@ import (
 )
 
 // Parse parses file reference on unix.
-func Parse(reference string, mediaType string) (filePath, mediatype string, err error) {
+func Parse(reference string, defaultMediaType string) (filePath, mediaType string, err error) {
+	filePath = reference
+	mediaType = defaultMediaType
 	i := strings.LastIndex(reference, ":")
 	if i >= 0 {
 		filePath, mediatype = reference[:i], reference[i+1:]