diff --git a/customize.html b/customize.html
index 430a01d2e..b760782df 100644
--- a/customize.html
+++ b/customize.html
@@ -1477,7 +1477,7 @@ window.onload = function () { // wait for load in a dumb way because B-0
       }
     }
 
-    if (!js) {
+    if (js) {
       var jsFolder = zip.folder('js')
       for (var fileName in js) {
         jsFolder.file(fileName, js[fileName])