diff --git a/install-dev/upgrade/php/drop_image_type_non_unique_index.php b/install-dev/upgrade/php/drop_image_type_non_unique_index.php
index bfb70d254..5a6c96eed 100644
--- a/install-dev/upgrade/php/drop_image_type_non_unique_index.php
+++ b/install-dev/upgrade/php/drop_image_type_non_unique_index.php
@@ -27,7 +27,8 @@
 
 function drop_image_type_non_unique_index()
 {
-	$index = Db::getInstance()->executeS('SHOW index FROM ps_image_type where column_name = "name" and non_unique=1');
+	$index = Db::getInstance()->executeS('SHOW index FROM `'._DB_PREFIX_.'image_type where column_name = "name" and non_unique=1');
 	// do not use pSql, this function is not defined
-	Db::getInstance()->execute('ALTER TABLE `PREFIX_image_type` DROP INDEX "'.$index.'"');
+	Db::getInstance()->execute('ALTER TABLE `'._DB_PREFIX_.'image_type` DROP INDEX "'.$index.'"');
 }
+
diff --git a/install-dev/upgrade/php/update_module_product_comments.php b/install-dev/upgrade/php/update_module_product_comments.php
index 8b7e2bad3..410360cc9 100644
--- a/install-dev/upgrade/php/update_module_product_comments.php
+++ b/install-dev/upgrade/php/update_module_product_comments.php
@@ -30,7 +30,7 @@ function update_module_product_comments()
 	if (Db::getInstance()->getValue('SELECT `id_module` FROM `'._DB_PREFIX_.'module` WHERE `name`="productcomments"'))
 	{
 		Db::getInstance()->execute('
-			CREATE TABLE IF NOT EXISTS `ps_product_comment_usefulness` (
+			CREATE TABLE IF NOT EXISTS `'._DB_PREFIX_.'product_comment_usefulness` (
 			  `id_product_comment` int(10) unsigned NOT NULL,
 			  `id_customer` int(10) unsigned NOT NULL,
 			  `usefulness` tinyint(1) unsigned NOT NULL,
@@ -38,7 +38,7 @@ function update_module_product_comments()
 			) ENGINE=ENGINE_TYPE DEFAULT CHARSET=utf8');
 
 		Db::getInstance()->execute('
-			CREATE TABLE IF NOT EXISTS `ps_product_comment_report` (
+			CREATE TABLE IF NOT EXISTS `'._DB_PREFIX_.'product_comment_report` (
 			  `id_product_comment` int(10) unsigned NOT NULL,
 			  `id_customer` int(10) unsigned NOT NULL,
 			  PRIMARY KEY (`id_product_comment`, `id_customer`)