diff --git a/lib/rack/tracker/google_analytics/template/google_analytics.erb b/lib/rack/tracker/google_analytics/template/google_analytics.erb
index 000ff7c..f2b1ecf 100644
--- a/lib/rack/tracker/google_analytics/template/google_analytics.erb
+++ b/lib/rack/tracker/google_analytics/template/google_analytics.erb
@@ -8,6 +8,10 @@
 
     ga('create', '<%= tracker %>', <%= tracker_options.to_json %>);
   }
+
+<% if options[:optimizer_id].present? %>
+  ga('require', '<%= options[:optimizer_id] %>');
+<% end %>
 <% if options[:enhanced_link_attribution] %>
   ga('require', 'linkid', 'linkid.js');
 <% end %>
@@ -41,4 +45,4 @@
 <% if tracker %>
   ga('send', 'pageview', <%= pageview_url_script %>);
 <% end %>
-</script>
+</script>
\ No newline at end of file