diff --git a/js/pgm_construction.js b/js/pgm_construction.js
index 3dd811694df3121277529445d820c4fa92de3fb0..ea87ab3f340b5582b578a9481deb5d28eab13f3c 100644
--- a/js/pgm_construction.js
+++ b/js/pgm_construction.js
@@ -221,12 +221,11 @@ function generate_blob() {
 
 /* propose the blob for download : save all data */
 function blob_download() {
-  var file = new File(
+  var blob = new Blob(
     [JSON.stringify(localStorage)],
-    'explosurf.json',
     {type : 'application/json'}
   ) ;
-  saveAs(file) ;
+  saveAs(blob, 'explosurf.json') ;
   /*
   var link = document.createElement('a') ;
   link.setAttribute('download', 'explosurf.json') ;