diff --git a/README.md b/README.md
index 2fd9cfbe..3a7e73e0 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,6 @@
 [Návod v češtině](#modul-pro-prestashop-17)
 
-# Module for PrestaShop 1.7
+# Module for PrestaShop 1.7, PrestaShop 8
 
 ### Download link
 [Download the latest version](https://github.com/Zasilkovna/prestashop/releases/latest)
@@ -75,7 +75,7 @@ In the **Orders** tab you will find a list of all orders for which the Packeta s
 - english
 
 ### Supported versions
-- PrestaShop version 1.7.x.
+- PrestaShop 1.7.x., PrestaShop 8
 - If you have problems using the module, please contact us at [e-commerce.support@packeta.com](mailto:e-commerce.support@packeta.com).
 
 ### Provided functions
@@ -102,12 +102,12 @@ Packeta module may not work with another OPC module.
 | Module version | Branch   | PHP version |
 |----------------|----------|-------------|
 | `>= 2.1.18`    | `master` | 5.6 - 8.2   | 
-| `>= 3.0`       | `v3.0.0` | 5.6 - 8.2   | 
+| `>= 3.0`       | `v3`     | 5.6 - 8.2   | 
 
 ### Further module limitations
 - Module does not currently support multistore.
 
-# Modul pro PrestaShop 1.7
+# Modul pro PrestaShop 1.7, PrestaShop 8
 
 ### Stažení modulu
 [Aktuální verze (Stáhnout »)](https://github.com/Zasilkovna/prestashop/releases/latest)
@@ -185,7 +185,7 @@ V záložce **objednávky** naleznete seznam všech objednávek u kterých byla
 - angličtina
 
 ### Podporovaná verze
-- PrestaShop verze 1.7.x.
+- PrestaShop 1.7.x., PrestaShop 8
 - Při problému s použitím modulu nás kontaktujte na adrese [e-commerce.support@packeta.com](mailto:e-commerce.support@packeta.com).
 
 ### Poskytované funkce
@@ -211,7 +211,7 @@ Modul Zásilkovny nemusí být s jiným OPC modulem funkční.
 | Verze modulu | Větev    | PHP verze |
 |--------------|----------|-----------|
 | `>= 2.1.18`  | `master` | 5.6 - 8.2 | 
-| `>= 3.0`     | `v3.0.0` | 5.6 - 8.2 | 
+| `>= 3.0`     | `v3`     | 5.6 - 8.2 | 
 
 ### Další omezení modulu
 - Modul v současné době nepodporuje multistore. 
diff --git a/packetery/CHANGE_LOG.txt b/packetery/CHANGE_LOG.txt
index 32de4d1f..fab6c5f9 100755
--- a/packetery/CHANGE_LOG.txt
+++ b/packetery/CHANGE_LOG.txt
@@ -1,3 +1,4 @@
+2.1.19 - Fixed: displaying the widget button and cart validation
 2.1.18 - Updated: compatibility with PrestaShop 8 ensured
 2.1.17 - Updated: sk "Is COD" translation update
        - Updated: improvements to the display of widget button in the cart
diff --git a/packetery/libs/Module/Helper.php b/packetery/libs/Module/Helper.php
new file mode 100644
index 00000000..14727841
--- /dev/null
+++ b/packetery/libs/Module/Helper.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace Packetery\Module;
+
+class Helper
+{
+
+    /**
+     * @param mixed $value
+     *
+     * @return bool
+     */
+    private static function isCastableToInt($value)
+    {
+        if (is_int($value)) {
+            return true;
+        }
+        if (is_string($value) && strlen((string)(float)$value) !== strlen($value)) {
+            return false;
+        }
+        if (is_float($value) || is_string($value)) {
+            if ($value <= PHP_INT_MAX && $value >= -PHP_INT_MAX) {
+                return (int)$value == $value;
+            }
+
+            return false;
+        }
+
+        return false;
+    }
+
+    /**
+     * @param array $array
+     *
+     * @return array
+     */
+    public static function typeCastableArrayItemsAsInts(array $array)
+    {
+        foreach ($array as $key => $value) {
+            if (self::isCastableToInt($value)) {
+                $array[$key] = (int)$value;
+            }
+        }
+
+        return $array;
+    }
+
+}
diff --git a/packetery/packetery.php b/packetery/packetery.php
index 20cc9596..dd5fc3fa 100755
--- a/packetery/packetery.php
+++ b/packetery/packetery.php
@@ -64,7 +64,7 @@ public function __construct()
     {
 		$this->name = 'packetery';
 		$this->tab = 'shipping_logistics';
-        $this->version = '2.1.18';
+        $this->version = '2.1.19';
 		$this->author = 'Packeta s.r.o.';
 		$this->need_instance = 0;
     	$this->is_configurable = 1;
@@ -568,8 +568,11 @@ public function hookDisplayCarrierExtraContent($params)
             );
             if (!$zPointCarriers) {
                 $zPointCarriers = [];
+            } else {
+                $zPointCarriers = array_column($zPointCarriers, 'id_carrier');
+                $zPointCarriers = Packetery\Module\Helper::typeCastableArrayItemsAsInts($zPointCarriers);
             }
-            $zPointCarriersIdsJSON = json_encode(array_column($zPointCarriers, 'id_carrier'));
+            $zPointCarriersIdsJSON = json_encode($zPointCarriers);
             $this->context->smarty->assign('zpoint_carriers', $zPointCarriersIdsJSON);
             $name_branch = '';
             $currency_branch = '';
diff --git a/packetery/views/js/front.js b/packetery/views/js/front.js
index a1b06af8..6234ef0f 100755
--- a/packetery/views/js/front.js
+++ b/packetery/views/js/front.js
@@ -266,10 +266,10 @@ tools = {
             }
 
             if ($extra.find('#open-packeta-widget').length) {
-                var carrierId = String($extra.find('#carrier_id').val());
+                var carrierId = parseInt($extra.find('#carrier_id').val());
                 var zpointCarriers = $extra.find('#zpoint_carriers').val();
                 zpointCarriers = JSON.parse(zpointCarriers);
-                if (!zpointCarriers.includes(parseInt(carrierId))) {
+                if (!zpointCarriers.includes(carrierId)) {
                     $extra.find('#open-packeta-widget').hide();
                     $extra.find('#selected-branch').hide();
                 }