diff --git a/classes/Cart.php b/classes/Cart.php
index dc72c75d2..04d39c1ab 100644
--- a/classes/Cart.php
+++ b/classes/Cart.php
@@ -830,6 +830,13 @@ class CartCore extends ObjectModel
 		$id_product_attribute = (int)$id_product_attribute;
 		$product = new Product($id_product, false, Configuration::get('PS_LANG_DEFAULT'), $shop->id);
 
+		if ($id_product_attribute)
+		{
+			$combination = new Combination((int)$id_product_attribute);
+			if ($combination->id_product != $id_product)
+				return false;
+		}
+
 		/* If we have a product combination, the minimal quantity is set with the one of this combination */
 		if (!empty($id_product_attribute))
 			$minimal_quantity = (int)Attribute::getAttributeMinimalQty($id_product_attribute);
diff --git a/classes/Currency.php b/classes/Currency.php
index fd22cb9f4..89dfa31cc 100644
--- a/classes/Currency.php
+++ b/classes/Currency.php
@@ -73,7 +73,7 @@ class CurrencyCore extends ObjectModel
 			'sign' => 			array('type' => self::TYPE_STRING, 'validate' => 'isGenericName', 'required' => true, 'size' => 8),
 			'format' => 		array('type' => self::TYPE_INT, 'validate' => 'isUnsignedId', 'required' => true),
 			'decimals' => 		array('type' => self::TYPE_BOOL, 'validate' => 'isBool', 'required' => true),
-			'conversion_rate' =>array('type' => self::TYPE_FLOAT, 'validate' => 'isFloat', 'required' => true),
+			'conversion_rate' =>array('type' => self::TYPE_FLOAT, 'validate' => 'isFloat', 'required' => true, 'shop' => true),
 			'deleted' => 		array('type' => self::TYPE_BOOL, 'validate' => 'isBool'),
 			'active' => 		array('type' => self::TYPE_BOOL, 'validate' => 'isBool'),
 		),
diff --git a/controllers/admin/AdminCurrenciesController.php b/controllers/admin/AdminCurrenciesController.php
index 12e92aa2f..28f5033fc 100644
--- a/controllers/admin/AdminCurrenciesController.php
+++ b/controllers/admin/AdminCurrenciesController.php
@@ -31,7 +31,6 @@ class AdminCurrenciesControllerCore extends AdminController
 		$this->table = 'currency';
 		$this->className = 'Currency';
 		$this->lang = false;
-		$this->multishop_context = Shop::CONTEXT_ALL;
 
 		$this->fields_list = array(
 			'id_currency' => array('title' => $this->l('ID'), 'align' => 'center', 'width' => 25),
@@ -69,6 +68,9 @@ class AdminCurrenciesControllerCore extends AdminController
 		);
 
 		parent::__construct();
+
+		$this->_select .= 'currency_shop.conversion_rate conversion_rate';
+		$this->_join .= Shop::addSqlAssociation('currency', 'a');
 	}
 
 	public function renderList()
diff --git a/controllers/admin/AdminLocalizationController.php b/controllers/admin/AdminLocalizationController.php
index 4641613f9..a136ea634 100644
--- a/controllers/admin/AdminLocalizationController.php
+++ b/controllers/admin/AdminLocalizationController.php
@@ -323,6 +323,10 @@ class AdminLocalizationControllerCore extends AdminController
 	public function updateOptionPsCurrencyDefault($value)
 	{
 		Configuration::updateValue('PS_CURRENCY_DEFAULT', $value);
+
+		/* Set conversion rate of default currency to 1 */
+		ObjectModel::updateMultishopTable('Currency', array('conversion_rate' => 1), 'a.id_currency');
+
 		Currency::refreshCurrencies();
 	}
 }
diff --git a/install-dev/data/db_structure.sql b/install-dev/data/db_structure.sql
index 307dc50d3..f07bfd5b4 100644
--- a/install-dev/data/db_structure.sql
+++ b/install-dev/data/db_structure.sql
@@ -2023,6 +2023,7 @@ CREATE TABLE `PREFIX_lang_shop` (
 CREATE TABLE `PREFIX_currency_shop` (
 `id_currency` INT( 11 ) UNSIGNED NOT NULL,
 `id_shop` INT( 11 ) UNSIGNED NOT NULL,
+`conversion_rate` decimal(13,6) NOT NULL,
   PRIMARY KEY (`id_currency`, `id_shop`),
 	KEY `id_shop` (`id_shop`)
 ) ENGINE=ENGINE_TYPE  DEFAULT CHARSET=utf8;
diff --git a/install-dev/upgrade/sql/1.5.3.0.sql b/install-dev/upgrade/sql/1.5.3.0.sql
index ca79b54f9..757b64804 100644
--- a/install-dev/upgrade/sql/1.5.3.0.sql
+++ b/install-dev/upgrade/sql/1.5.3.0.sql
@@ -23,3 +23,6 @@ INSERT INTO `PREFIX_configuration`(`name`, `value`, `date_add`, `date_upd`) VALU
 ALTER TABLE `PREFIX_order_cart_rule` CHANGE `name` `name` VARCHAR(254);
 
 ALTER TABLE `PREFIX_cart` CHANGE `delivery_option` `delivery_option` TEXT CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT '';
+
+ALTER TABLE `PREFIX_currency_shop` ADD `conversion_rate` DECIMAL( 13, 6 ) NOT NULL;
+UPDATE `PREFIX_currency_shop` a SET `conversion_rate` = (SELECT `conversion_rate` FROM `PREFIX_currency` b WHERE a.id_currency = b.id_currency);