diff --git a/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb b/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb
index 29ecdd469..3358a665a 100644
--- a/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb
+++ b/app/assets/javascripts/discourse/lib/emoji/emoji.js.erb
@@ -32,7 +32,7 @@ for (var name in aliases) {
 Discourse.Emoji.unescape = function(string) {
   if (Discourse.SiteSettings.enable_emoji && string.indexOf(":") >= 0) {
     string = string.replace(/:[^\s:]+:?/g, function(m) {
-      const emoji = Discourse.Emoji.translations[m] ? Discourse.Emoji.translations[m] : m.slice(1, m.length - 1),
+      var emoji = Discourse.Emoji.translations[m] ? Discourse.Emoji.translations[m] : m.slice(1, m.length - 1),
             url = Discourse.Emoji.urlFor(emoji);
       return url ? "<img src='" + url + "' title='" + emoji + "' alt='" + emoji + "' class='emoji'>" : m;
     });
diff --git a/config/initializers/10-discourse_iife.rb b/config/initializers/10-discourse_iife.rb
index 4df28e58c..122c2922b 100644
--- a/config/initializers/10-discourse_iife.rb
+++ b/config/initializers/10-discourse_iife.rb
@@ -1,7 +1,7 @@
 require 'discourse_iife'
 
 Rails.application.assets.register_preprocessor('application/javascript', DiscourseIIFE)
-unless Rails.env.production?
+unless Rails.env.production? || ENV["DISABLE_EVAL"]
   require 'source_url'
   Rails.application.assets.register_postprocessor('application/javascript', SourceURL)
 end