diff --git a/Model/Config.php b/Model/Config.php
index e644bd1..48c6e8e 100644
--- a/Model/Config.php
+++ b/Model/Config.php
@@ -13,6 +13,7 @@ class Config
     private const IS_ENABLED = 'hyva_themes_checkout/new_customer/enable';
     private const SEND_RESET_PASSWORD_MAIL = 'hyva_themes_checkout/new_customer/send_reset_password_mail';
     private const NEW_PASSWORD_TEMPLATE = 'hyva_themes_checkout/new_customer/create_password_template';
+    private const DEFAULT_CUSTOMER_GROUP_XML_PATH = 'customer/create_account/default_group';
 
     public function __construct(private ScopeConfigInterface $scopeConfig)
     {
@@ -41,4 +42,13 @@ public function getNewPasswordTemplate(): string
             ScopeInterface::SCOPE_STORE
         );
     }
+
+    public function getDefaultCustomerGroup(?int $storeId = null): int
+    {
+        return (int)$this->scopeConfig->getValue(
+            self::DEFAULT_CUSTOMER_GROUP_XML_PATH,
+            ScopeInterface::SCOPE_STORE,
+            $storeId
+        );
+    }
 }
diff --git a/Observer/ConvertGuestToCustomer.php b/Observer/ConvertGuestToCustomer.php
index 11376b0..60ec7a9 100644
--- a/Observer/ConvertGuestToCustomer.php
+++ b/Observer/ConvertGuestToCustomer.php
@@ -56,7 +56,7 @@ public function execute(Observer $observer): void
         $quote->setCustomerId($customer->getId())
             ->setCustomerIsGuest(0)
             // Ideally we should make this configurable.
-            ->setCustomerGroupId(\Magento\Customer\Api\Data\GroupInterface::NOT_LOGGED_IN_ID);
+            ->setCustomerGroupId($this->newAccountConfig->getDefaultCustomerGroup((int)$quote->getStoreId()));
 
         /** @var \Magento\Sales\Model\Order $order */
         $order = $observer->getEvent()->getOrder();