diff --git a/admin-dev/themes/template/orders/_customized_data.tpl b/admin-dev/themes/template/orders/_customized_data.tpl
index a3dd0e43d..4890d9af5 100755
--- a/admin-dev/themes/template/orders/_customized_data.tpl
+++ b/admin-dev/themes/template/orders/_customized_data.tpl
@@ -87,7 +87,7 @@
 				<input type="hidden" name="totalQty" id="totalQty" value="{$customization['quantity']}" />
 				<input type="hidden" name="productName" id="productName" value="{$product['product_name']}" />
 			{if ((!$order->hasBeenDelivered() OR Configuration::get('PS_ORDER_RETURN')) && (int)(($customization['quantity_returned']) < (int)($customization['quantity'])))}
-				<input type="checkbox" name="id_customization[{$customizationId}]" id="id_customization[{$customizationId}]" value="{$product['id_order_detail']}" onchange="setCancelQuantity(this, '{$customizationId}', '{$customization['quantity']}')" '.{if (($customization['quantity_returned'] + $customization['quantity_refunded']) >= $customization['quantity'])}disabled="disabled"{/if} />
+				<input type="checkbox" name="id_customization[{$customizationId}]" id="id_customization[{$customizationId}]" value="{$product['id_order_detail']}" onchange="setCancelQuantity(this, '{$customizationId}', '{$customization['quantity'] - $customization['quantity_refunded']}')" '.{if (($customization['quantity_returned'] + $customization['quantity_refunded']) >= $customization['quantity'])}disabled="disabled"{/if} />
 			{else}
 				--
 			{/if}
@@ -106,4 +106,4 @@
 			</td>
 		</tr>
 	{/foreach}
-{/if}
\ No newline at end of file
+{/if}
diff --git a/classes/Customization.php b/classes/Customization.php
index 4bef8fa75..34e38d0d0 100644
--- a/classes/Customization.php
+++ b/classes/Customization.php
@@ -81,8 +81,8 @@ class CustomizationCore
 		$in_values  = '';
 		foreach($ids_customizations as $key => $id_customization)
 		{
-			if ($key > 0) $in_values += ',';
-			$in_values += (int)($id_customization);
+			if ($key > 0) $in_values .= ',';
+			$in_values .= (int)($id_customization);
 		}
 
 		if (!empty($in_values))