diff --git a/src/Form/Type/OrderItemType.php b/src/Form/Type/OrderItemType.php
index e251d2d..a935463 100644
--- a/src/Form/Type/OrderItemType.php
+++ b/src/Form/Type/OrderItemType.php
@@ -5,10 +5,9 @@
 namespace Setono\SyliusOrderEditPlugin\Form\Type;
 
 use Sylius\Bundle\ResourceBundle\Form\Type\AbstractResourceType;
+use Sylius\Bundle\ResourceBundle\Form\Type\ResourceAutocompleteChoiceType;
 use Sylius\Component\Core\Model\OrderItemInterface;
-use Sylius\Component\Core\Model\ProductVariant;
 use Sylius\Component\Order\Modifier\OrderItemQuantityModifierInterface;
-use Symfony\Bridge\Doctrine\Form\Type\EntityType;
 use Symfony\Component\Form\Extension\Core\Type\IntegerType;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Form\FormEvent;
@@ -37,10 +36,13 @@ public function buildForm(FormBuilderInterface $builder, array $options): void
                     $this->orderItemQuantityModifier->modify($orderItem, $quantity);
                 },
             ])
-            // TODO: change to autocomplete type for product variant
-            ->add('variant', EntityType::class, [
-                'class' => ProductVariant::class,
-                'choice_label' => 'code',
+            ->add('variant', ResourceAutocompleteChoiceType::class, [
+                'label' => false,
+                'multiple' => false,
+                'required' => true,
+                'choice_name' => 'descriptor',
+                'choice_value' => 'id',
+                'resource' => 'sylius.product_variant',
             ])
         ;
 
diff --git a/src/Resources/public/js/order-edit.js b/src/Resources/public/js/order-edit.js
index 1898c05..437e4d0 100644
--- a/src/Resources/public/js/order-edit.js
+++ b/src/Resources/public/js/order-edit.js
@@ -23,7 +23,11 @@ document.querySelector('button.add-order-item').addEventListener('click', (event
     orderItemTable.dataset.index++;
 
     var rows = orderItemTable.querySelectorAll('form[name="sylius_order"] tbody tr');
-    var lastItemRowDeleteButton = rows[rows.length - 2].querySelector('button.delete-order-item');
+    var lastItemRow = rows[rows.length - 2];
+    var lastItemRowDeleteButton = lastItemRow.querySelector('button.delete-order-item');
+
+    $(lastItemRow).find('.sylius-autocomplete').autoComplete();
+
     lastItemRowDeleteButton.addEventListener('click', (event) => {
         var row = event.currentTarget.closest('tr');
         row.nextElementSibling.remove();
diff --git a/src/Resources/views/admin/order/update/theme.html.twig b/src/Resources/views/admin/order/update/theme.html.twig
index 3ec8e54..b6cb8cb 100644
--- a/src/Resources/views/admin/order/update/theme.html.twig
+++ b/src/Resources/views/admin/order/update/theme.html.twig
@@ -3,7 +3,14 @@
 {% block _sylius_order_items_entry_widget %}
     <tr class="item">
         <td>{{ form_widget(form.quantity) }}</td>
-        <td>{{ form_widget(form.variant) }}</td>
+        <td>
+            {{ form_row(form.variant, {
+                'remote_url': path('sylius_admin_ajax_all_product_variants_by_phrase'),
+                'remote_criteria_type': 'contains',
+                'remote_criteria_name': 'phrase',
+                'load_edit_url': path('sylius_admin_ajax_all_product_variants_by_codes')}
+            ) }}
+        </td>
         <td colspan="4" class="right aligned">
             <button class="ui red labeled icon button delete-order-item" type="button">
                 <i class="icon trash"></i> {{ 'sylius.ui.delete'|trans }}
diff --git a/src/Setter/OrderDiscountAdjustmentSetter.php b/src/Setter/OrderDiscountAdjustmentSetter.php
index 5e50755..7dfbc43 100644
--- a/src/Setter/OrderDiscountAdjustmentSetter.php
+++ b/src/Setter/OrderDiscountAdjustmentSetter.php
@@ -20,15 +20,18 @@ public function __construct(
 
     public function set(OrderInterface $order, int $discount): void
     {
-        $items = $order->getItems();
+        /** @var array<int, OrderItemInterface> $items */
+        $items = $order->getItems()->getValues();
         $orderId = (int) $order->getId();
 
-        $distributedPrices = $this->integerDistributor->distribute($discount, $items->count());
+        $distributedPrices = $this->integerDistributor->distribute($discount, count($items));
 
-        /** @var int $distribution */
+        /**
+         * @var int $i
+         * @var int $distribution
+         */
         foreach ($distributedPrices as $i => $distribution) {
-            /** @var OrderItemInterface $item */
-            $item = $items->get($i);
+            $item = $items[$i];
             $this->orderItemDiscountAdjustmentAdder->add(
                 $item,
                 AdjustmentTypes::SETONO_ADMIN_ORDER_DISCOUNT,