diff --git a/lib/custom_wizard/extensions/topic_extension.rb b/lib/custom_wizard/extensions/topic_extension.rb
index e890f9df..7ee442ed 100644
--- a/lib/custom_wizard/extensions/topic_extension.rb
+++ b/lib/custom_wizard/extensions/topic_extension.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 DiscourseEvent.on(:before_create_topic) do |topic_params, user|
   category = topic_params.category
   if category&.custom_fields&.[]('create_topic_wizard').present?