diff --git a/classes/Product.php b/classes/Product.php
index 9d0a84254..bcc9a0772 100644
--- a/classes/Product.php
+++ b/classes/Product.php
@@ -1633,6 +1633,7 @@ class ProductCore extends ObjectModel
 				LEFT JOIN `'._DB_PREFIX_.'attribute_lang` al ON (a.`id_attribute` = al.`id_attribute` AND al.`id_lang` = '.(int)$id_lang.')
 				LEFT JOIN `'._DB_PREFIX_.'attribute_group_lang` agl ON (ag.`id_attribute_group` = agl.`id_attribute_group` AND agl.`id_lang` = '.(int)$id_lang.')
 				WHERE pa.`id_product` = '.(int)$this->id.'
+				GROUP BY pa.`id_product_attribute`, ag.`id_attribute_group`
 				ORDER BY pa.`id_product_attribute`';
 
 		$res = Db::getInstance()->executeS($sql);
@@ -1676,6 +1677,7 @@ class ProductCore extends ObjectModel
 				LEFT JOIN `'._DB_PREFIX_.'attribute_group_lang` agl ON (ag.`id_attribute_group` = agl.`id_attribute_group` AND agl.`id_lang` = '.(int)$id_lang.')
 				WHERE pa.`id_product` = '.(int)$this->id.'
 				AND pa.`id_product_attribute` = '.(int)$id_product_attribute.'
+				GROUP BY pa.`id_product_attribute`, ag.`id_attribute_group`
 				ORDER BY pa.`id_product_attribute`';
 
 		$res = Db::getInstance()->executeS($sql);