diff --git a/htdocs/bom/class/bom.class.php b/htdocs/bom/class/bom.class.php
index 6935ac2594d..e36415b4077 100644
--- a/htdocs/bom/class/bom.class.php
+++ b/htdocs/bom/class/bom.class.php
@@ -600,7 +600,7 @@ class BOM extends CommonObject
 	 * @param	int		$fk_default_workstation	Default workstation
 	 * @return	int								Return integer <0 if KO, Id of created object if OK
 	 */
-	public function addLine($fk_product, $qty, $qty_frozen = 0, $disable_stock_change = 0, $efficiency = 1.0, $position = -1, $fk_bom_child = null, $import_key = null, $fk_unit = '', $array_options = array(), $fk_default_workstation = null)
+	public function addLine($fk_product, $qty, $qty_frozen = 0, $disable_stock_change = 0, $efficiency = 1.0, $position = -1, $fk_bom_child = null, $import_key = null, $fk_unit = 0, $array_options = array(), $fk_default_workstation = null)
 	{
 		global $mysoc, $conf, $langs, $user;