diff --git a/app/helpers/checkout_helper.rb b/app/helpers/checkout_helper.rb
index 9f21588ee6..72779dd4ec 100644
--- a/app/helpers/checkout_helper.rb
+++ b/app/helpers/checkout_helper.rb
@@ -18,7 +18,7 @@ module CheckoutHelper
     enterprise_fee_adjustments = adjustments.select { |a| a.originator_type == 'EnterpriseFee' && a.source_type != 'Spree::LineItem' }
     adjustments.reject! { |a| a.originator_type == 'EnterpriseFee' && a.source_type != 'Spree::LineItem' }
     unless exclude.include? :admin_and_handling
-      adjustments << Spree::Adjustment.new(label: I18n.t(:orders_form_admin), amount: enterprise_fee_adjustments.sum(&:amount))
+      adjustments << Spree::Adjustment.new(label: I18n.t(:orders_form_admin), amount: enterprise_fee_adjustments.sum(:amount))
     end
 
     adjustments
diff --git a/app/models/spree/line_item.rb b/app/models/spree/line_item.rb
index cbe411fdeb..c2da5814d6 100644
--- a/app/models/spree/line_item.rb
+++ b/app/models/spree/line_item.rb
@@ -178,7 +178,7 @@ module Spree
     end
 
     def included_tax
-      adjustments.included_tax.sum(&:included_tax)
+      adjustments.included_tax.sum(:included_tax)
     end
 
     def tax_rates
diff --git a/app/models/spree/order.rb b/app/models/spree/order.rb
index c2a0a98582..3d844aa8e7 100644
--- a/app/models/spree/order.rb
+++ b/app/models/spree/order.rb
@@ -729,15 +729,15 @@ module Spree
     end
 
     def shipping_tax
-      adjustments(:reload).shipping.sum(&:included_tax)
+      adjustments(:reload).shipping.sum(:included_tax)
     end
 
     def enterprise_fee_tax
-      adjustments(:reload).enterprise_fee.sum(&:included_tax)
+      adjustments(:reload).enterprise_fee.sum(:included_tax)
     end
 
     def total_tax
-      (adjustments + price_adjustments).sum(&:included_tax)
+      (adjustments.to_a + price_adjustments.to_a).sum(&:included_tax)
     end
 
     def price_adjustments
diff --git a/app/serializers/api/order_serializer.rb b/app/serializers/api/order_serializer.rb
index cbac0c00b4..427c222ea2 100644
--- a/app/serializers/api/order_serializer.rb
+++ b/app/serializers/api/order_serializer.rb
@@ -16,7 +16,7 @@ module Api
     end
 
     def item_count
-      object.line_items.sum(&:quantity)
+      object.line_items.sum(:quantity)
     end
 
     def completed_at
diff --git a/app/services/order_adjustments_fetcher.rb b/app/services/order_adjustments_fetcher.rb
index 560f04bdb1..9292fe8e91 100644
--- a/app/services/order_adjustments_fetcher.rb
+++ b/app/services/order_adjustments_fetcher.rb
@@ -1,7 +1,7 @@
 # This class allows orders with eager-loaded adjustment objects to calculate various adjustment
 # types without triggering additional queries.
 #
-# For example; `order.adjustments.shipping.sum(&:amount)` would normally trigger a new query
+# For example; `order.adjustments.shipping.sum(:amount)` would normally trigger a new query
 # regardless of whether or not adjustments have been preloaded, as `#shipping` is an adjustment
 # scope, eg; `scope :shipping, where(originator_type: 'Spree::ShippingMethod')`.
 #
diff --git a/app/views/producer_mailer/order_cycle_report.html.haml b/app/views/producer_mailer/order_cycle_report.html.haml
index cc78f43ecd..8acda45749 100644
--- a/app/views/producer_mailer/order_cycle_report.html.haml
+++ b/app/views/producer_mailer/order_cycle_report.html.haml
@@ -37,13 +37,13 @@
           %td
             #{raw(product_and_full_name)}
           %td.text-right
-            #{line_items.sum(&:quantity)}
+            #{line_items.sum(:quantity)}
           %td.text-right
             #{line_items.first.single_money}
           %td.text-right
             #{Spree::Money.new(line_items.sum(&:total), currency: line_items.first.currency) }
           %td.tax.text-right
-            #{Spree::Money.new(line_items.sum(&:included_tax), currency: line_items.first.currency) }
+            #{Spree::Money.new(line_items.sum(:included_tax), currency: line_items.first.currency) }
       %tr.total-row
         %td
         %td
diff --git a/app/views/producer_mailer/order_cycle_report.text.haml b/app/views/producer_mailer/order_cycle_report.text.haml
index c322c3cac5..4de8b60808 100644
--- a/app/views/producer_mailer/order_cycle_report.text.haml
+++ b/app/views/producer_mailer/order_cycle_report.text.haml
@@ -13,7 +13,7 @@ Orders summary
 = t :producer_mail_order_text
 \
 - @grouped_line_items.each_pair do |product_and_full_name, line_items|
-  #{line_items.first.variant.sku} - #{raw(line_items.first.product.supplier.name)} - #{raw(product_and_full_name)} (QTY: #{line_items.sum(&:quantity)}) @ #{line_items.first.single_money} = #{Spree::Money.new(line_items.sum(&:total), currency: line_items.first.currency)}
+  #{line_items.first.variant.sku} - #{raw(line_items.first.product.supplier.name)} - #{raw(product_and_full_name)} (QTY: #{line_items.sum(:quantity)}) @ #{line_items.first.single_money} = #{Spree::Money.new(line_items.sum(&:total), currency: line_items.first.currency)}
 \
 \
 #{t :total}: #{@total}
diff --git a/lib/open_food_network/group_buy_report.rb b/lib/open_food_network/group_buy_report.rb
index 2cd4f23c20..45c9c9dbcd 100644
--- a/lib/open_food_network/group_buy_report.rb
+++ b/lib/open_food_network/group_buy_report.rb
@@ -38,7 +38,7 @@ module OpenFoodNetwork
           # Cycle thorugh variant of a product
           variant_groups = line_items_by_product.group_by(&:variant)
           variant_groups.each do |variant, line_items_by_variant|
-            sum_quantities = line_items_by_variant.sum(&:quantity)
+            sum_quantities = line_items_by_variant.sum(:quantity)
             sum_max_quantities = line_items_by_variant.sum { |li| li.max_quantity || 0 }
             variants_and_quantities << GroupBuyVariantRow.new(variant, sum_quantities, sum_max_quantities)
           end
diff --git a/lib/open_food_network/orders_and_fulfillments_report/customer_totals_report.rb b/lib/open_food_network/orders_and_fulfillments_report/customer_totals_report.rb
index 3edbd71cf7..0ea53af020 100644
--- a/lib/open_food_network/orders_and_fulfillments_report/customer_totals_report.rb
+++ b/lib/open_food_network/orders_and_fulfillments_report/customer_totals_report.rb
@@ -134,7 +134,7 @@ module OpenFoodNetwork
           proc { |line_items| line_items.first.variant.product.name },
           proc { |line_items| line_items.first.variant.full_name },
 
-          proc { |line_items| line_items.sum(&:quantity) },
+          proc { |line_items| line_items.sum(:quantity) },
           proc { |line_items| line_items.sum(&:amount) },
           proc { |line_items| line_items.sum(&:amount_with_adjustments) },
           proc { |_line_items| "" },
diff --git a/lib/open_food_network/orders_and_fulfillments_report/default_report.rb b/lib/open_food_network/orders_and_fulfillments_report/default_report.rb
index 4f59edd4bf..a503be84a0 100644
--- a/lib/open_food_network/orders_and_fulfillments_report/default_report.rb
+++ b/lib/open_food_network/orders_and_fulfillments_report/default_report.rb
@@ -45,7 +45,7 @@ module OpenFoodNetwork
           supplier_name,
           product_name,
           line_items_name,
-          proc { |line_items| line_items.sum(&:quantity) },
+          proc { |line_items| line_items.sum(:quantity) },
           proc { |line_items| line_items.first.price },
           proc { |line_items| line_items.sum { |li| li.quantity * li.price } },
           proc { |_line_items| "" },
diff --git a/lib/open_food_network/orders_and_fulfillments_report/distributor_totals_by_supplier_report.rb b/lib/open_food_network/orders_and_fulfillments_report/distributor_totals_by_supplier_report.rb
index 8e3c810045..cfb1a1f3f9 100644
--- a/lib/open_food_network/orders_and_fulfillments_report/distributor_totals_by_supplier_report.rb
+++ b/lib/open_food_network/orders_and_fulfillments_report/distributor_totals_by_supplier_report.rb
@@ -59,7 +59,7 @@ module OpenFoodNetwork
          proc { |line_items| line_items.first.variant.product.supplier.name },
          proc { |line_items| line_items.first.variant.product.name },
          proc { |line_items| line_items.first.variant.full_name },
-         proc { |line_items| line_items.sum(&:quantity) },
+         proc { |line_items| line_items.sum(:quantity) },
          proc { |line_items| line_items.first.price },
          proc { |line_items| line_items.sum(&:amount) },
          proc { |_line_items| "" },
diff --git a/lib/open_food_network/orders_and_fulfillments_report/supplier_totals_by_distributor_report.rb b/lib/open_food_network/orders_and_fulfillments_report/supplier_totals_by_distributor_report.rb
index 42c3523e00..cddc962f49 100644
--- a/lib/open_food_network/orders_and_fulfillments_report/supplier_totals_by_distributor_report.rb
+++ b/lib/open_food_network/orders_and_fulfillments_report/supplier_totals_by_distributor_report.rb
@@ -60,7 +60,7 @@ module OpenFoodNetwork
           proc { |line_items| line_items.first.variant.product.name },
           proc { |line_items| line_items.first.variant.full_name },
           proc { |line_items| line_items.first.order.distributor.name },
-          proc { |line_items| line_items.sum(&:quantity) },
+          proc { |line_items| line_items.sum(:quantity) },
           proc { |line_items| line_items.first.price },
           proc { |line_items| line_items.sum(&:amount) },
           proc { |_line_items| I18n.t(:report_header_shipping_method) }
diff --git a/lib/open_food_network/orders_and_fulfillments_report/supplier_totals_report.rb b/lib/open_food_network/orders_and_fulfillments_report/supplier_totals_report.rb
index 09755adb1b..3029cf19b3 100644
--- a/lib/open_food_network/orders_and_fulfillments_report/supplier_totals_report.rb
+++ b/lib/open_food_network/orders_and_fulfillments_report/supplier_totals_report.rb
@@ -44,7 +44,7 @@ module OpenFoodNetwork
           supplier_name,
           product_name,
           line_items_name,
-          proc { |line_items| line_items.sum(&:quantity) },
+          proc { |line_items| line_items.sum(:quantity) },
           proc { |line_items| total_units(line_items) },
           proc { |line_items| line_items.first.price },
           proc { |line_items| line_items.sum(&:amount) },
diff --git a/lib/open_food_network/payments_report.rb b/lib/open_food_network/payments_report.rb
index 3c2fbbd24b..7cfc6342f4 100644
--- a/lib/open_food_network/payments_report.rb
+++ b/lib/open_food_network/payments_report.rb
@@ -92,28 +92,28 @@ module OpenFoodNetwork
         [proc { |payments| payments.first.order.payment_state },
          proc { |payments| payments.first.order.distributor.name },
          proc { |payments| payments.first.payment_method.name },
-         proc { |payments| payments.sum(&:amount) }]
+         proc { |payments| payments.sum(:amount) }]
       when "itemised_payment_totals"
         [proc { |orders| orders.first.payment_state },
          proc { |orders| orders.first.distributor.name },
-         proc { |orders| orders.sum(&:item_total) },
+         proc { |orders| orders.sum(:item_total) },
          proc { |orders| orders.sum(&:ship_total) },
          proc { |orders| orders.sum(&:outstanding_balance) },
-         proc { |orders| orders.sum(&:total) }]
+         proc { |orders| orders.sum(:total) }]
       when "payment_totals"
         [proc { |orders| orders.first.payment_state },
          proc { |orders| orders.first.distributor.name },
-         proc { |orders| orders.sum(&:item_total) },
+         proc { |orders| orders.sum(:item_total) },
          proc { |orders| orders.sum(&:ship_total) },
-         proc { |orders| orders.sum(&:total) },
-         proc { |orders| orders.sum { |o| o.payments.select { |payment| payment.completed? && (payment.payment_method.name.to_s.include? "EFT") }.sum(&:amount) } },
-         proc { |orders| orders.sum { |o| o.payments.select { |payment| payment.completed? && (payment.payment_method.name.to_s.include? "PayPal") }.sum(&:amount) } },
+         proc { |orders| orders.sum(:total) },
+         proc { |orders| orders.sum { |o| o.payments.select { |payment| payment.completed? && (payment.payment_method.name.to_s.include? "EFT") }.sum(:amount) } },
+         proc { |orders| orders.sum { |o| o.payments.select { |payment| payment.completed? && (payment.payment_method.name.to_s.include? "PayPal") }.sum(:amount) } },
          proc { |orders| orders.sum(&:outstanding_balance) }]
       else
         [proc { |payments| payments.first.order.payment_state },
          proc { |payments| payments.first.order.distributor.name },
          proc { |payments| payments.first.payment_method.name },
-         proc { |payments| payments.sum(&:amount) }]
+         proc { |payments| payments.sum(:amount) }]
       end
     end
   end
diff --git a/lib/open_food_network/sales_tax_report.rb b/lib/open_food_network/sales_tax_report.rb
index 458b4523af..d7a8863b28 100644
--- a/lib/open_food_network/sales_tax_report.rb
+++ b/lib/open_food_network/sales_tax_report.rb
@@ -101,7 +101,7 @@ module OpenFoodNetwork
     end
 
     def tax_included_in(line_item)
-      line_item.adjustments.sum(&:included_tax)
+      line_item.adjustments.sum(:included_tax)
     end
 
     def shipment_inc_vat
diff --git a/lib/open_food_network/xero_invoices_report.rb b/lib/open_food_network/xero_invoices_report.rb
index 90a43e54c8..2821cbdb98 100644
--- a/lib/open_food_network/xero_invoices_report.rb
+++ b/lib/open_food_network/xero_invoices_report.rb
@@ -188,32 +188,32 @@ module OpenFoodNetwork
     end
 
     def total_untaxable_fees(order)
-      order.adjustments.enterprise_fee.without_tax.sum(&:amount)
+      order.adjustments.enterprise_fee.without_tax.sum(:amount)
     end
 
     def total_taxable_fees(order)
-      order.adjustments.enterprise_fee.with_tax.sum(&:amount)
+      order.adjustments.enterprise_fee.with_tax.sum(:amount)
     end
 
     def total_shipping(order)
-      order.adjustments.shipping.sum(&:amount)
+      order.adjustments.shipping.sum(:amount)
     end
 
     def total_transaction(order)
-      order.adjustments.payment_fee.sum(&:amount)
+      order.adjustments.payment_fee.sum(:amount)
     end
 
     def tax_on_shipping_s(order)
-      tax_on_shipping = order.adjustments.shipping.sum(&:included_tax) > 0
+      tax_on_shipping = order.adjustments.shipping.sum(:included_tax) > 0
       tax_on_shipping ? I18n.t(:report_header_gst_on_income) : I18n.t(:report_header_gst_free_income)
     end
 
     def total_untaxable_admin_adjustments(order)
-      order.adjustments.admin.without_tax.sum(&:amount)
+      order.adjustments.admin.without_tax.sum(:amount)
     end
 
     def total_taxable_admin_adjustments(order)
-      order.adjustments.admin.with_tax.sum(&:amount)
+      order.adjustments.admin.with_tax.sum(:amount)
     end
 
     def detail?
diff --git a/spec/models/concerns/variant_stock_spec.rb b/spec/models/concerns/variant_stock_spec.rb
index ef173bd5f3..5bdb119047 100644
--- a/spec/models/concerns/variant_stock_spec.rb
+++ b/spec/models/concerns/variant_stock_spec.rb
@@ -26,7 +26,7 @@ describe VariantStock do
       end
 
       it 'returns the total items in stock anyway' do
-        expect(variant.on_hand).to eq(variant.stock_items.sum(&:count_on_hand))
+        expect(variant.on_hand).to eq(variant.stock_items.sum(:count_on_hand))
       end
     end
 
@@ -39,7 +39,7 @@ describe VariantStock do
 
       it 'returns the total items in stock' do
         expect(variant.on_hand)
-          .to eq(variant.stock_items.sum(&:count_on_hand))
+          .to eq(variant.stock_items.sum(:count_on_hand))
       end
     end
   end