diff --git a/htdocs/product/class/html.formproduct.class.php b/htdocs/product/class/html.formproduct.class.php
index 1bafd063dec..3070515b020 100644
--- a/htdocs/product/class/html.formproduct.class.php
+++ b/htdocs/product/class/html.formproduct.class.php
@@ -316,8 +316,6 @@ class FormProduct
 
 		$return = '';
 
-		$measuring_units = array();
-
 		require_once DOL_DOCUMENT_ROOT . '/core/class/cunits.class.php';
 		$measuringUnits = new CUnits($db);
         $result = $measuringUnits->fetchAll(
@@ -340,7 +338,7 @@ class FormProduct
 
 			foreach ($measuringUnits->records as $lines) {
 				$return .= '<option value="' . $lines->code . '"';
-				if ($key == $default) {
+				if ($lines->code == $default) {
 					$return .= ' selected';
 				}
 				// $return.= '>'.$value.'</option>';