diff --git a/spec/services/bulk_invoice_service_spec.rb b/spec/services/bulk_invoice_service_spec.rb
index 52fe085288..1ff3d9edab 100644
--- a/spec/services/bulk_invoice_service_spec.rb
+++ b/spec/services/bulk_invoice_service_spec.rb
@@ -49,12 +49,25 @@ describe BulkInvoiceService do
   end
 
   describe "#orders_from" do
+    let(:renderer) { InvoiceRenderer.new }
+
+    before do
+      allow(InvoiceRenderer).to receive(:new).and_return(renderer)
+    end
+
     it "orders with completed desc" do
       order_old = create(:order_with_distributor, :completed, completed_at: 2.minutes.ago)
+      order_oldest = create(:order_with_distributor, :completed, completed_at: 4.minutes.ago)
       order_older = create(:order_with_distributor, :completed, completed_at: 3.minutes.ago)
 
-      expect(service.send(:orders_from, [order_older.id, order_old.id]).pluck(:id))
-        .to eq([order_old.id, order_older.id])
+      # This is the creation order provided `find_each` which invalidates
+      # our intended sorting by `completed_at`:
+      expect(renderer).to receive(:render_to_string).with(order_old).ordered.and_return("")
+      expect(renderer).to receive(:render_to_string).with(order_oldest).ordered.and_return("")
+      expect(renderer).to receive(:render_to_string).with(order_older).ordered.and_return("")
+
+      order_ids = [order_oldest, order_old, order_older].map(&:id)
+      service.start_pdf_job_without_delay(order_ids)
     end
   end
 end