diff --git a/app/models/spree/shipment.rb b/app/models/spree/shipment.rb
index 993fa0f62c..99d3a57fc0 100644
--- a/app/models/spree/shipment.rb
+++ b/app/models/spree/shipment.rb
@@ -107,11 +107,14 @@ module Spree
     def refresh_rates
       return shipping_rates if shipped?
 
+      # The call to Stock::Estimator below will replace the current shipping_method
+      original_shipping_method_id = shipping_method.try(:id)
+
       self.shipping_rates = OrderManagement::Stock::Estimator.new(order).shipping_rates(to_package)
 
-      if shipping_method
+      if original_shipping_method_id
         selected_rate = shipping_rates.detect { |rate|
-          rate.shipping_method_id == shipping_method.id
+          rate.shipping_method_id == original_shipping_method_id
         }
         self.selected_shipping_rate_id = selected_rate.id if selected_rate
       end