diff --git a/app/overrides/super_good/solidus_taxjar/spree/order_updater/fire_recalculated_event.rb b/app/overrides/super_good/solidus_taxjar/spree/order_updater/fire_recalculated_event.rb
index 1e169bc3..df66124e 100644
--- a/app/overrides/super_good/solidus_taxjar/spree/order_updater/fire_recalculated_event.rb
+++ b/app/overrides/super_good/solidus_taxjar/spree/order_updater/fire_recalculated_event.rb
@@ -4,6 +4,10 @@ module SuperGood
   module SolidusTaxjar
     module Spree
       module OrderUpdater
+        # Responsible for introducing the `order_recalculated` event for older
+        # versions of Solidus (from 2.9 up until but not including 2.11) which
+        # do not have this event. TaxJar transaction reporting relies on this
+        # event firing when an order is recalculated.
         module FireRecalculatedEvent
           def persist_totals
             ::Spree::Event.fire 'order_recalculated', order: order
diff --git a/lib/super_good/engine.rb b/lib/super_good/engine.rb
index 3d94c855..a1fcaa77 100644
--- a/lib/super_good/engine.rb
+++ b/lib/super_good/engine.rb
@@ -5,6 +5,9 @@ class Engine < Rails::Engine
     isolate_namespace Spree
     engine_name 'super_good_solidus_taxjar'
 
+    # Solidus versions prior to 2.11.0 do not support auto-loading of subscribers
+    # so we need to manually register the reporting subscriber with the event
+    # bus.
     if Spree.solidus_gem_version < Gem::Version.new('2.11.0')
       require root.join('app/subscribers/super_good/solidus_taxjar/spree/reporting_subscriber')
       SuperGood::SolidusTaxjar::Spree::ReportingSubscriber.subscribe!
diff --git a/spec/models/spree/order_updater_spec.rb b/spec/models/spree/order_updater_spec.rb
index 69ecdc93..2b627c7b 100644
--- a/spec/models/spree/order_updater_spec.rb
+++ b/spec/models/spree/order_updater_spec.rb
@@ -1,12 +1,45 @@
 RSpec.describe Spree::OrderUpdater do
   describe '#update' do
+    subject { described_class.new(order).update }
+
+    let(:order) { create(:order) }
+
+    module TestSubscriber
+      include Spree::Event::Subscriber
+      include SolidusSupport::LegacyEventCompat::Subscriber
+
+      event_action :order_recalculated
+
+      def order_recalculated(_event)
+      end
+    end
+
+    if SolidusSupport::LegacyEventCompat.using_legacy?
+      let(:event_type_class) { ActiveSupport::Notifications::Event }
+
+      before do
+        if TestSubscriber.respond_to?(:subscribe!)
+          TestSubscriber.subscribe!
+        else
+          TestSubscriber.activate
+        end
+      end
+    else
+      let(:event_type_class) { Omnes::UnstructuredEvent }
+
+      before { TestSubscriber.omnes_subscriber.subscribe_to(Spree::Bus) }
+    end
+
     it 'fires the order_recalculated event exactly once' do
-      stub_const('Spree::Event', class_spy(Spree::Event))
-      order = create(:order)
+      allow(TestSubscriber).to receive(:order_recalculated)
 
-      described_class.new(order).update
+      subject
 
-      expect(Spree::Event).to have_received(:fire).with('order_recalculated', order: order).once
+      expect(TestSubscriber).to have_received(:order_recalculated)
+        .with(instance_of(event_type_class))
+        .once do |event|
+          expect(event.payload[:order]).to eq(order)
+        end
     end
   end
 end