diff --git a/classes/Category.php b/classes/Category.php
index a2b576022..b129ed194 100644
--- a/classes/Category.php
+++ b/classes/Category.php
@@ -647,7 +647,7 @@ class CategoryCore extends ObjectModel
 					ON p.`id_product` = cp.`id_product`
 				LEFT JOIN `'._DB_PREFIX_.'product_attribute` pa
 				ON (p.`id_product` = pa.`id_product`)
-				'.Shop::addSqlAssociation('product_attribute', 'pa', false, 'product_attribute_shop.default_on = 1').'
+				'.Shop::addSqlAssociation('product_attribute', 'pa', false).'
 				'.Shop::addSqlAssociation('product', 'p').'
 				'.Product::sqlStock('p', 'pa', false, $context->shop).'
 				LEFT JOIN `'._DB_PREFIX_.'category_lang` cl
@@ -675,6 +675,7 @@ class CategoryCore extends ObjectModel
 				LEFT JOIN `'._DB_PREFIX_.'manufacturer` m
 					ON m.`id_manufacturer` = p.`id_manufacturer`
 				WHERE product_shop.`id_shop` = '.(int)Context::getContext()->shop->id.'
+					AND (product_attribute_shop.default_on = 1 OR product_attribute_shop.default_on IS NULL)
 					AND cp.`id_category` = '.(int)$this->id
 					.($active ? ' AND product_shop.`active` = 1' : '')
 					.($front ? ' AND product_shop.`visibility` IN ("both", "catalog")' : '')
diff --git a/classes/Manufacturer.php b/classes/Manufacturer.php
index 68a9f911f..21f3ab47d 100644
--- a/classes/Manufacturer.php
+++ b/classes/Manufacturer.php
@@ -184,6 +184,7 @@ class ManufacturerCore extends ObjectModel
 			)
 			'.Shop::addSqlAssociation('manufacturer', 'm').
 			($active ? ' AND m.`active` = 1' : '').'
+			GROUP BY m.id_manufacturer
 			ORDER BY m.`name` ASC'.
 			($p ? ' LIMIT '.(((int)$p - 1) * (int)$n).','.(int)$n : '');
 
@@ -337,7 +338,7 @@ class ManufacturerCore extends ObjectModel
 				'.Shop::addSqlAssociation('product', 'p').'
 				LEFT JOIN `'._DB_PREFIX_.'product_attribute` pa
 					ON (p.`id_product` = pa.`id_product`)
-				'.Shop::addSqlAssociation('product_attribute', 'pa', false, 'product_attribute_shop.default_on = 1').'
+				'.Shop::addSqlAssociation('product_attribute', 'pa', false).'
 				LEFT JOIN `'._DB_PREFIX_.'product_lang` pl
 					ON (p.`id_product` = pl.`id_product` AND pl.`id_lang` = '.(int)$id_lang.Shop::addSqlRestrictionOnLang('pl').')
 				LEFT JOIN `'._DB_PREFIX_.'image` i
@@ -359,14 +360,15 @@ class ManufacturerCore extends ObjectModel
 				WHERE p.`id_manufacturer` = '.(int)$id_manufacturer.'
 				'.($active ? ' AND product_shop.`active` = 1' : '').'
 				'.($front ? ' AND product_shop.`visibility` IN ("both", "catalog")' : '').'
-					AND p.`id_product` IN (
-						SELECT cp.`id_product`
-						FROM `'._DB_PREFIX_.'category_group` cg
-						LEFT JOIN `'._DB_PREFIX_.'category_product` cp
-							ON (cp.`id_category` = cg.`id_category`)'.
+				AND (product_attribute_shop.default_on = 1 OR product_attribute_shop.default_on IS NULL)
+				AND p.`id_product` IN (
+					SELECT cp.`id_product`
+					FROM `'._DB_PREFIX_.'category_group` cg
+					LEFT JOIN `'._DB_PREFIX_.'category_product` cp
+						ON (cp.`id_category` = cg.`id_category`)'.
 					($active_category ? ' INNER JOIN `'._DB_PREFIX_.'category` ca ON cp.`id_category` = ca.`id_category` AND ca.`active` = 1' : '').'
-						WHERE cg.`id_group` '.$sql_groups.'
-					)
+					WHERE cg.`id_group` '.$sql_groups.'
+				)
 				ORDER BY '.(($order_by == 'id_product') ? 'p.' : '').pSQL($order_by).' '.pSQL($order_way).'
 				LIMIT '.(((int)$p - 1) * (int)$n).','.(int)$n;
 
diff --git a/classes/Product.php b/classes/Product.php
index 37b40f87a..9cb1a8d94 100644
--- a/classes/Product.php
+++ b/classes/Product.php
@@ -1827,7 +1827,7 @@ class ProductCore extends ObjectModel
 			$sql->select('pa.id_product_attribute');
 			$sql->leftOuterJoin('product_attribute', 'pa', 'p.`id_product` = pa.`id_product`');
 			$sql->join(Shop::addSqlAssociation('product_attribute', 'pa', false));
-			$sql->where('product_attribute_shop.default_on = 1');
+			$sql->where('(product_attribute_shop.default_on = 1 OR product_attribute_shop.default_on IS NULL)');
 		}
 
 		$result = Db::getInstance(_PS_USE_SQL_SLAVE_)->executeS($sql);