diff --git a/pkg/overlay/pack.go b/pkg/overlay/pack.go
index 3a6cc7d7..41cabd03 100644
--- a/pkg/overlay/pack.go
+++ b/pkg/overlay/pack.go
@@ -301,7 +301,11 @@ func generateBlob(layerType types.LayerType, contents string, ociDir string) (io
 	if layerType.Type == "tar" {
 		packOptions := layer.RepackOptions{TranslateOverlayWhiteouts: true}
 		blob = layer.GenerateInsertLayer(contents, "/", false, &packOptions)
-		mediaType = ispec.MediaTypeImageLayer
+		blob, err = mutate.GzipCompressor.WithOpt(gzipBlockSize).Compress(blob)
+		if err != nil {
+			return nil, "", "", err
+		}
+		mediaType = ispec.MediaTypeImageLayerGzip
 	} else {
 		blob, mediaType, rootHash, err = squashfs.MakeSquashfs(ociDir, contents, nil, layerType.Verity)
 		if err != nil {