diff --git a/apps/devhub/templates/devhub/base.html b/apps/devhub/templates/devhub/base.html
index 08da4a637a..97cfe0f0ee 100644
--- a/apps/devhub/templates/devhub/base.html
+++ b/apps/devhub/templates/devhub/base.html
@@ -5,6 +5,10 @@
 {% endif %}
 {% block bodyclass %}developer-hub {{ editable }}{% endblock %}
 
+{% block bodyattrs %}
+{% if addon %}data-default-locale="{{ addon.default_locale|lower }}"{% endif %}
+{% endblock %}
+
 {% block title %}{{ dev_page_title() }}{% endblock %}
 
 {% block extrahead %}
diff --git a/media/css/zamboni/zamboni.css b/media/css/zamboni/zamboni.css
index 06b93d7abd..86ca3b39e4 100644
--- a/media/css/zamboni/zamboni.css
+++ b/media/css/zamboni/zamboni.css
@@ -3193,6 +3193,16 @@ input.ui-autocomplete-loading {
     background-color: #2A4364;
 }
 
+.trans [lang] {
+    display: none;
+}
+.trans [lang]:first-child {
+    display: block;
+}
+.trans .init-trans {
+    display: none;
+}
+
 .trans .cloned {
     color: #ccc;
     font-style: italic;
diff --git a/media/js/zamboni/l10n.js b/media/js/zamboni/l10n.js
index 35142283ef..464456ee43 100644
--- a/media/js/zamboni/l10n.js
+++ b/media/js/zamboni/l10n.js
@@ -1,13 +1,17 @@
 // Yes, this is out here for a reason.
 // We want to hide the non-default locales as fast as possible.
-if ($('.default-locale').length) {
-    $(format(".trans :not([lang={0}])", [$('.default-locale').attr('href').substring(1)])).hide();
-}
+(function() {
+    var dl = $('body').attr("data-default-locale");
+    if (dl) {
+        $(format(".trans :not([lang={0}])", dl)).hide();
+        $(format(".trans [lang={0}]", dl)).show();
+    }
+})();
 
 $(document).ready(function () {
     if (!$("#l10n-menu").length) return;
     var locales = [],
-        dl = $('.default-locale').attr('href').substring(1),
+        dl = $('body').attr("data-default-locale"),
         currentLocale = dl,
         unsavedModalMsg = $('#modal-l10n-unsaved .msg').html(),
         unsavedModal = $('#modal-l10n-unsaved').modal(),
@@ -175,11 +179,16 @@ $(document).ready(function () {
                 field = $el.attr('data-name'),
                 label = $(format("label[data-for={0}]",[field]));
             if (!$el.find(format("[lang={0}]",[lang])).length) {
-                var $ni = $el.children(format("[lang={0}]",[dl])).clone();
-                $ni.addClass("cloned").attr("lang", lang);
+                var $ni = $el.children(".init-trans").clone();
+                $ni.attr({
+                    class: "cloned",
+                    lang: lang,
+                });
                 if ($ni.is(':not(span)')) {
-                    $ni.attr('id',format('id_{0}_{1}',[field,lang]))
-                       .attr('name',[field,lang].join('_'));
+                    $ni.attr({
+                        id: format('id_{0}_{1}', field, lang),
+                        name: [field,lang].join('_')
+                    });
                 }
                 $el.append($ni);
             }
@@ -192,8 +201,8 @@ $(document).ready(function () {
             }
 
         });
-        $(format(".trans [lang!={0}]", [currentLocale])).hide();
-        $(format(".trans [lang={0}]", [lang])).show();
+        $(format(".trans :not([lang={0}])", currentLocale)).hide();
+        $(format(".trans [lang={0}]", currentLocale)).show();
         initCharCount();
     }
 
diff --git a/templates/base.html b/templates/base.html
index eaa655f4b3..878e92d679 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -29,7 +29,8 @@
         data-appid="{{ request.APP.id }}"
         data-anonymous="{{ (not request.user.is_authenticated())|json }}"
         data-readonly="{{ settings.READ_ONLY|json }}"
-        data-media-url="{{ MEDIA_URL }}">
+        data-media-url="{{ MEDIA_URL }}"
+        {% block bodyattrs %}{% endblock %}>
 
     {% if request.ADMIN_MESSAGE or settings.READ_ONLY%}
       <div id="site-notice">