diff --git a/lib/file.js b/lib/file.js
index 51490471..340ff37f 100644
--- a/lib/file.js
+++ b/lib/file.js
@@ -114,7 +114,7 @@ File.prototype.getBlobURL = function (cb) {
     if (err) return cb(err)
     var ext = path.extname(self.name).toLowerCase()
     var type = mime[ext]
-    var blob = new window.Blob([ buffer ], type && { type: type })
+    var blob = type ? new window.Blob([ buffer ], { type: type }) : new window.Blob([ buffer ])
     var url = window.URL.createObjectURL(blob)
     cb(null, url)
   })