diff --git a/htdocs/product/class/product.class.php b/htdocs/product/class/product.class.php
index f8ae29aebc5..95853d28676 100644
--- a/htdocs/product/class/product.class.php
+++ b/htdocs/product/class/product.class.php
@@ -897,7 +897,7 @@ class Product extends CommonObject
 			$sql.= ", accountancy_code_sell= '" . $this->db->escape($this->accountancy_code_sell)."'";
 			$sql.= ", accountancy_code_sell_intra= '" . $this->db->escape($this->accountancy_code_sell_intra)."'";
 			$sql.= ", accountancy_code_sell_export= '" . $this->db->escape($this->accountancy_code_sell_export)."'";
-			$sql.= ", desiredstock = " . ((isset($this->desiredstock) && $this->desiredstock != '') ? $this->desiredstock : "null");
+			$sql.= ", desiredstock = " . ((isset($this->desiredstock) && is_numeric($this->desiredstock)) ? $this->desiredstock : "null");
 			$sql.= ", cost_price = " . ($this->cost_price != '' ? $this->db->escape($this->cost_price) : 'null');
 	        $sql.= ", fk_unit= " . (!$this->fk_unit ? 'NULL' : $this->fk_unit);
 	        $sql.= ", price_autogen = " . (!$this->price_autogen ? 0 : 1);