diff --git a/www/ponyfills.js b/www/ponyfills.js
index 3b509a3..b13d774 100644
--- a/www/ponyfills.js
+++ b/www/ponyfills.js
@@ -16,7 +16,7 @@ module.exports = function init(global) {
     } else if (global.Blob && value instanceof global.Blob) {
       // mimic File instance by adding missing properties
       value.lastModifiedDate = new Date();
-      value.name = fileName !== undefined ? fileName : 'blob';
+      value.name = filename !== undefined ? filename : 'blob';
     } else {
       value = String(value);
     }
@@ -44,4 +44,4 @@ module.exports = function init(global) {
   }
 
   return interface;
-};
\ No newline at end of file
+};