diff --git a/cmd/oras/push.go b/cmd/oras/push.go
index 582de27c7..74e6aafad 100644
--- a/cmd/oras/push.go
+++ b/cmd/oras/push.go
@@ -81,7 +81,7 @@ Example - Push file to the HTTP registry:
 	cmd.Flags().StringVarP(&opts.manifestAnnotations, "manifest-annotations", "", "", "manifest annotation file")
 	cmd.Flags().StringVarP(&opts.manifestExport, "export-manifest", "", "", "export the pushed manifest")
 	cmd.Flags().StringVarP(&opts.artifactType, "artifact-type", "", "", "artifact type")
-	cmd.Flags().StringVarP(&opts.artifactRefs, "artifact-reference", "", "", "artifact reference")
+	cmd.Flags().StringVarP(&opts.artifactRefs, "subject", "s", "", "subject artifact")
 	cmd.Flags().BoolVarP(&opts.pathValidationDisabled, "disable-path-validation", "", false, "skip path validation")
 	cmd.Flags().BoolVarP(&opts.verbose, "verbose", "v", false, "verbose output")
 	cmd.Flags().BoolVarP(&opts.debug, "debug", "d", false, "debug mode")
diff --git a/pkg/oras/push.go b/pkg/oras/push.go
index f7ea8d8f4..ff5b3ca6a 100644
--- a/pkg/oras/push.go
+++ b/pkg/oras/push.go
@@ -93,6 +93,7 @@ func pack(provider content.Provider, descriptors []ocispec.Descriptor, opts *pus
 		artifact := *opts.artifact
 		artifact.Blobs = convertV1DescriptorsToV2(descriptors)
 		artifact.Annotations = opts.manifestAnnotations
+		mediaType = artifactspec.MediaTypeArtifactManifest
 		content = artifact
 	} else {
 		mediaType = ocispec.MediaTypeImageManifest