diff --git a/themes/intotheeast/templates/gpx-manager.html.twig b/themes/intotheeast/templates/gpx-manager.html.twig
index 3ed28d5..9bf5135 100644
--- a/themes/intotheeast/templates/gpx-manager.html.twig
+++ b/themes/intotheeast/templates/gpx-manager.html.twig
@@ -139,7 +139,7 @@ function initUpload(formEl) {
         btn.disabled = true;
 
         const fd = new FormData();
-        fd.append('file', new File([file], slugifyFilename(file.name), { type: file.type }));
+        fd.append('file', file, slugifyFilename(file.name));
 
         const res = await apiFetch(`${API}/pages${route}/media`, { method: 'POST', body: fd });
         btn.disabled = false;