diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 4ff3dacb537..98807af1858 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -1413,7 +1413,7 @@ class Form
 				}
 			}
 			if ($showempty) {
-				$out .= '<option value="-1" data-html="'.dol_escape_htmltag('<span class="opacitymedium">'.$textifempty.'</span>').'">'.$textifempty.'</option>'."\n";
+				$out .= '<option value="-1" data-html="'.dol_escape_htmltag('<span class="opacitymedium">'.($textifempty ? $textifempty : '&nbsp;').'</span>').'">'.$textifempty.'</option>'."\n";
 			}
 
 			$num = $this->db->num_rows($resql);