diff --git a/util/imagetools/create.go b/util/imagetools/create.go
index fa168b1a..71853e07 100644
--- a/util/imagetools/create.go
+++ b/util/imagetools/create.go
@@ -80,12 +80,15 @@ func (r *Resolver) Combine(ctx context.Context, srcs []*Source, ann []string, pr
 	// on single source, return original bytes
 	if len(srcs) == 1 && len(ann) == 0 {
 		switch srcs[0].Desc.MediaType {
-		case images.MediaTypeDockerSchema2Manifest:
+		// if the source is already an image index or manifest list, there is no need to consider the value
+		// of preferIndex since if set to true then the source is already in the preferred format, and if false
+		// it doesn't matter since we're not going to split it into separate manifests
+		case images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
+			return dts[0], srcs[0].Desc, nil
+		default:
 			if !preferIndex {
 				return dts[0], srcs[0].Desc, nil
 			}
-		case images.MediaTypeDockerSchema2ManifestList, ocispec.MediaTypeImageIndex:
-			return dts[0], srcs[0].Desc, nil
 		}
 	}