diff --git a/handler/upload.go b/handler/upload.go
index da1aaed..b36997e 100644
--- a/handler/upload.go
+++ b/handler/upload.go
@@ -294,6 +294,7 @@ func (h *Handler) getButton(w http.ResponseWriter, r *http.Request) {
 	mime := button.BlobMIME
 	w.Header().Add("Content-Type", mime)
 	w.Header().Add("Content-Length", fmt.Sprintf("%d", stats.Size()))
+	w.Header().Add("Cache-Control", "public, max-age=31536000, immutable")
 
 	img, err := os.Open(imgPath)
 	if err != nil {