diff --git a/assets/javascripts/wizard/lib/wizard-i18n.js.es6 b/assets/javascripts/wizard/lib/wizard-i18n.js.es6
index 17242e58..26247bc0 100644
--- a/assets/javascripts/wizard/lib/wizard-i18n.js.es6
+++ b/assets/javascripts/wizard/lib/wizard-i18n.js.es6
@@ -1,7 +1,7 @@
 import I18n from "I18n";
 
 const getThemeId = () => {
-  let themeId = parseInt($("meta[name=discourse_theme_ids]")[0].content, 10);
+  let themeId = parseInt(document.querySelector("meta[name=discourse_theme_id]").content, 10);
 
   if (!isNaN(themeId)) {
     return themeId.toString();
diff --git a/controllers/custom_wizard/wizard.rb b/controllers/custom_wizard/wizard.rb
index 9670fd62..bac15fa9 100644
--- a/controllers/custom_wizard/wizard.rb
+++ b/controllers/custom_wizard/wizard.rb
@@ -6,7 +6,7 @@ class CustomWizard::WizardController < ::ApplicationController
 
   before_action :ensure_plugin_enabled
   helper_method :wizard_page_title
-  helper_method :wizard_theme_ids
+  helper_method :wizard_theme_id
   helper_method :wizard_theme_lookup
   helper_method :wizard_theme_translations_lookup
 
@@ -20,16 +20,16 @@ class CustomWizard::WizardController < ::ApplicationController
     wizard ? (wizard.name || wizard.id) : I18n.t('wizard.custom_title')
   end
 
-  def wizard_theme_ids
-    wizard ? [wizard.theme_id] : nil
+  def wizard_theme_id
+    wizard ? wizard.theme_id : nil
   end
 
   def wizard_theme_lookup(name)
-    Theme.lookup_field(wizard_theme_ids, mobile_view? ? :mobile : :desktop, name)
+    Theme.lookup_field(wizard_theme_id, mobile_view? ? :mobile : :desktop, name)
   end
 
   def wizard_theme_translations_lookup
-    Theme.lookup_field(wizard_theme_ids, :translations, I18n.locale)
+    Theme.lookup_field(wizard_theme_id, :translations, I18n.locale)
   end
 
   def index
diff --git a/views/layouts/wizard.html.erb b/views/layouts/wizard.html.erb
index efa09734..16d119b7 100644
--- a/views/layouts/wizard.html.erb
+++ b/views/layouts/wizard.html.erb
@@ -4,8 +4,8 @@
 
     <%= discourse_stylesheet_link_tag :wizard, theme_id: nil %>
     <%= discourse_stylesheet_link_tag :wizard_custom %>
-    <%- if wizard_theme_ids.present? %>
-      <%= discourse_stylesheet_link_tag (mobile_view? ? :mobile_theme : :desktop_theme), theme_ids: wizard_theme_ids %>
+    <%- if wizard_theme_id.present? %>
+      <%= discourse_stylesheet_link_tag (mobile_view? ? :mobile_theme : :desktop_theme), theme_id: wizard_theme_id %>
     <%- end %>
 
     <%= preload_script "locales/#{I18n.locale}" %>
@@ -29,7 +29,7 @@
 
     <%= tag.meta id: 'data-discourse-setup', data: client_side_setup_data %>
 
-    <meta name="discourse_theme_ids" content="<%= wizard_theme_ids&.join(",") %>">
+    <meta name="discourse_theme_id" content="<%= wizard_theme_id %>">
     <meta name="discourse-base-uri" content="<%= Discourse.base_path %>">
 
     <%= render partial: "layouts/head" %>