diff --git a/classes/ProductSupplier.php b/classes/ProductSupplier.php
index bcc65863e..810590568 100644
--- a/classes/ProductSupplier.php
+++ b/classes/ProductSupplier.php
@@ -195,7 +195,7 @@ class ProductSupplierCore extends ObjectModel
 	public static function getSupplierCollection($id_product, $group_by_supplier = true)
 	{
 		$suppliers = new Collection('ProductSupplier');
-		$suppliers->where('id_product', '=', $id_product);
+		$suppliers->where('id_product', '=', (int)$id_product);
 
 		if ($group_by_supplier)
 			$suppliers->groupBy('id_supplier');
diff --git a/controllers/admin/AdminSuppliersController.php b/controllers/admin/AdminSuppliersController.php
index 2be2512e6..901ab9ec1 100644
--- a/controllers/admin/AdminSuppliersController.php
+++ b/controllers/admin/AdminSuppliersController.php
@@ -400,6 +400,9 @@ class AdminSuppliersControllerCore extends AdminController
 				$this->errors[] = $this->l('It is not possible to delete a supplier if there are any pending supply order.');
 			else
 			{
+				//delete all product_supplier linked to this supplier
+				Db::getInstance()->execute('DELETE FROM `'._DB_PREFIX_.'product_supplier` WHERE `id_supplier`='.(int)$obj->id); 
+				
 				$id_address = Address::getAddressIdBySupplierId($obj->id);
 				$address = new Address($id_address);
 				if (Validate::isLoadedObject($address))