diff --git a/lib/sidekiq/web/helpers.rb b/lib/sidekiq/web/helpers.rb
index 46222b1b..c2e5dfd2 100644
--- a/lib/sidekiq/web/helpers.rb
+++ b/lib/sidekiq/web/helpers.rb
@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 require 'uri'
+require 'set'
 require 'yaml'
 
 module Sidekiq