diff --git a/app/models/qbo_invoice.rb b/app/models/qbo_invoice.rb
index 1865f0c..2485cf1 100644
--- a/app/models/qbo_invoice.rb
+++ b/app/models/qbo_invoice.rb
@@ -69,7 +69,7 @@ class QboInvoice < ActiveRecord::Base
 
             # Attach the invoice to the issue
             unless i.qbo_invoices.include?(qbo_invoice)
-              i.qbo_invoices << qbo_invoice
+              i.qbo_invoices << qbo_invoice.id
               i.qbo_invoices.save!
             end
           rescue