diff --git a/classes/Customer.php b/classes/Customer.php
index 55429fcb3..e6bccab43 100644
--- a/classes/Customer.php
+++ b/classes/Customer.php
@@ -42,7 +42,7 @@ class CustomerCore extends ObjectModel
 	public $id_gender = 0;
 
 	/** @var integer Default group ID */
-	public $id_default_group = _PS_DEFAULT_CUSTOMER_GROUP_;
+	public $id_default_group;
 
 	/** @var string Lastname */
 	public $lastname;
@@ -189,7 +189,13 @@ class CustomerCore extends ObjectModel
 	protected static $_defaultGroupId = array();
 	protected static $_customerHasAddress = array();
 	protected static $_customer_groups = array();
-
+	
+	public function __contruct($id = null)
+	{
+		$this->id_default_group = (int)Configuration::get('PS_CUSTOMER_GROUP');
+		parent::__construct($id);
+	}
+	
 	public function add($autodate = true, $null_values = true)
 	{
 		$this->id_shop = ($this->id_shop) ? $this->id_shop : Context::getContext()->shop->id;
@@ -201,11 +207,11 @@ class CustomerCore extends ObjectModel
 		if ($this->newsletter && !Validate::isDate($this->newsletter_date_add))
 			$this->newsletter_date_add = date('Y-m-d H:i:s');
 			
-		if ($this->id_default_group == _PS_DEFAULT_CUSTOMER_GROUP_)
+		if ($this->id_default_group == Configuration::get('PS_CUSTOMER_GROUP'))
 			if ($this->is_guest)
-				$this->id_default_group = Configuration::get('PS_GUEST_GROUP');
+				$this->id_default_group = (int)Configuration::get('PS_GUEST_GROUP');
 			else
-				$this->id_default_group = Configuration::get('PS_CUSTOMER_GROUP');
+				$this->id_default_group = (int)Configuration::get('PS_CUSTOMER_GROUP');
 
 		/* Can't create a guest customer, if this feature is disabled */
 		if ($this->is_guest && !Configuration::get('PS_GUEST_CHECKOUT_ENABLED'))
diff --git a/classes/Group.php b/classes/Group.php
index 5ae7322bd..464112be8 100644
--- a/classes/Group.php
+++ b/classes/Group.php
@@ -157,7 +157,7 @@ class GroupCore extends ObjectModel
 
 	public function delete()
 	{
-		if ($this->id == _PS_DEFAULT_CUSTOMER_GROUP_)
+		if ($this->id == (int)Configuration::get('PS_CUSTOMER_GROUP'))
 			return false;
 		if (parent::delete())
 		{
diff --git a/classes/LocalizationPack.php b/classes/LocalizationPack.php
index 251e2059a..8c0bccfa1 100644
--- a/classes/LocalizationPack.php
+++ b/classes/LocalizationPack.php
@@ -432,7 +432,7 @@ class LocalizationPackCore
 			$attributes = $xml->group_default->attributes();
 			if (isset($attributes['price_display_method']) && in_array((int)$attributes['price_display_method'], array(0, 1)))
 			{
-				$group = new Group((int)_PS_DEFAULT_CUSTOMER_GROUP_);
+				$group = new Group((int)Configuration::get('PS_CUSTOMER_GROUP'));
 				$group->price_display_method = (int)$attributes['price_display_method'];
 				if (!$group->save())
 					$this->_errors[] = Tools::displayError('An error occurred during the default group update');
diff --git a/classes/Product.php b/classes/Product.php
index e22850083..9a25030fa 100644
--- a/classes/Product.php
+++ b/classes/Product.php
@@ -2399,7 +2399,7 @@ class ProductCore extends ObjectModel
 		if (!Validate::isBool($usetax) || !Validate::isUnsignedId($id_product))
 			die(Tools::displayError());
 		// Initializations
-		$id_group = (isset($context->customer) ? $context->customer->id_default_group : _PS_DEFAULT_CUSTOMER_GROUP_);
+		$id_group = (isset($context->customer) ? $context->customer->id_default_group : (int)Configuration::get('PS_CUSTOMER_GROUP'));
 
 		// If there is cart in context or if the specified id_cart is different from the context cart id
 		if (!is_object($cur_cart) || (Validate::isUnsignedInt($id_cart) && $id_cart && $cur_cart->id != $id_cart))
diff --git a/classes/webservice/WebserviceRequest.php b/classes/webservice/WebserviceRequest.php
index 2df91e930..75c94b6be 100644
--- a/classes/webservice/WebserviceRequest.php
+++ b/classes/webservice/WebserviceRequest.php
@@ -333,7 +333,7 @@ class WebserviceRequestCore
 			$id_country = (int)(isset($value['country']) ? $value['country'] : (Configuration::get('PS_COUNTRY_DEFAULT')));
 			$id_state = (int)(isset($value['state']) ? $value['state'] : 0);
 			$id_currency = (int)(isset($value['currency']) ? $value['currency'] : Configuration::get('PS_CURRENCY_DEFAULT'));
-			$id_group = (int)(isset($value['group']) ? $value['group'] : Configuration::get('_PS_DEFAULT_CUSTOMER_GROUP_'));
+			$id_group = (int)(isset($value['group']) ? $value['group'] : (int)Configuration::get('PS_CUSTOMER_GROUP'));
 			$quantity = (int)(isset($value['quantity']) ? $value['quantity'] : 1);
 			$use_tax = (int)(isset($value['use_tax']) ? $value['use_tax'] : Configuration::get('PS_TAX'));
 			$decimals = (int)(isset($value['decimals']) ? $value['decimals'] : Configuration::get('PS_PRICE_ROUND_MODE'));
diff --git a/config/defines.inc.php b/config/defines.inc.php
index c4e9e5940..8ce70b580 100755
--- a/config/defines.inc.php
+++ b/config/defines.inc.php
@@ -142,7 +142,7 @@ define('_STOCK_MOVEMENT_MISSING_REASON_', 4);
 
 /**
  * @deprecated 1.5.0.1
- * @see const PS_CUSTOMER_GROUP
+ * @see Configuration::get('PS_CUSTOMER_GROUP')
  */
 define('_PS_DEFAULT_CUSTOMER_GROUP_', 3);
 
diff --git a/controllers/front/ProductController.php b/controllers/front/ProductController.php
index 3c1935468..c57997bbd 100644
--- a/controllers/front/ProductController.php
+++ b/controllers/front/ProductController.php
@@ -275,7 +275,7 @@ class ProductControllerCore extends FrontController
 	protected function assignPriceAndTax()
 	{
 		$id_customer = (isset($this->context->customer) ? (int)$this->context->customer->id : 0);
-		$id_group = (isset($this->context->customer) ? $this->context->customer->id_default_group : _PS_DEFAULT_CUSTOMER_GROUP_);
+		$id_group = (isset($this->context->customer) ? $this->context->customer->id_default_group : (int)Configuration::get('PS_CUSTOMER_GROUP'));
 		$id_country = (int)$id_customer ? Customer::getCurrentCountry($id_customer) : Configuration::get('PS_COUNTRY_DEFAULT');
 
 		$group_reduction = GroupReduction::getValueForProduct($this->product->id, $id_group);