diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index 3793ac78..8a5092aa 100644
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -14,7 +14,7 @@
     = stylesheet_link_tag 'application', media: 'all',
       'data-turbolinks-track' => true
     = javascript_include_tag 'application', 'data-turbolinks-track' => true,
-      type: 'text/javascript', defer: true, async: true
+      type: 'text/javascript', defer: true, async: Rails.env.production?
     = csrf_meta_tags
 
   - classes = [request.domain ? request.domain.split('.')[0] : '',