diff --git a/app/jobs/warehouse/update_mailing_info_job.rb b/app/jobs/warehouse/update_mailing_info_job.rb
index 39a25ea..fe275f3 100644
--- a/app/jobs/warehouse/update_mailing_info_job.rb
+++ b/app/jobs/warehouse/update_mailing_info_job.rb
@@ -16,7 +16,7 @@ class Warehouse::UpdateMailingInfoJob < ApplicationJob
       "ship_client",
       startDate: start_date,
       endDate: end_date
-    ).index_by { |order| order[:order_number].sub("hack.club/", "") }
+    ).index_by { |order| order[:order_number].to_s.sub("hack.club/", "") }
 
     orders.each do |order|
       zen_order = zen_orders[order.hc_id]