diff --git a/htdocs/core/class/extrafields.class.php b/htdocs/core/class/extrafields.class.php
index 9c1d9c3a105..05bed3c8039 100644
--- a/htdocs/core/class/extrafields.class.php
+++ b/htdocs/core/class/extrafields.class.php
@@ -1147,7 +1147,7 @@ class ExtraFields
 			}
 
 			$out.='<select class="flat '.$morecss.' maxwidthonsmartphone" name="'.$keyprefix.$key.$keysuffix.'" id="'.$keyprefix.$key.$keysuffix.'" '.($moreparam?$moreparam:'').'>';
-			if (!$required)	$out.='<option value="0">&nbsp;</option>';
+			$out .= '<option value="">&nbsp;</option>';
 			foreach ($param['options'] as $key => $val)
 			{
 				if ((string) $key == '') continue;
@@ -1258,7 +1258,7 @@ class ExtraFields
                     dol_syslog(get_class($this) . '::showInputField type=sellist', LOG_DEBUG);
                     $resql = $this->db->query($sql);
                     if ($resql) {
-						if (!$required) $out .= '<option value="0">&nbsp;</option>';
+						$out .= '<option value="">&nbsp;</option>';
                         $num = $this->db->num_rows($resql);
                         $i = 0;
                         while ($i < $num) {
@@ -1323,7 +1323,7 @@ class ExtraFields
                 } else {
 					require_once DOL_DOCUMENT_ROOT . '/categories/class/categorie.class.php';
                     $data = $form->select_all_categories(Categorie::$MAP_ID_TO_CODE[$InfoFieldList[5]], '', 'parent', 64, $InfoFieldList[6], 1, 1);
-					if (!$required) $out .= '<option value="0">&nbsp;</option>';
+					$out .= '<option value="">&nbsp;</option>';
                     foreach ($data as $data_key => $data_value) {
                         $out .= '<option value="' . $data_key . '"';
                         $out .= ($value == $data_key ? ' selected' : '');