diff --git a/htdocs/core/class/html.form.class.php b/htdocs/core/class/html.form.class.php
index 56990effeb2..df2cd57ca05 100644
--- a/htdocs/core/class/html.form.class.php
+++ b/htdocs/core/class/html.form.class.php
@@ -4784,7 +4784,7 @@ class Form
 	 *    @param	int			            $outputmode			0=HTML select string, 1=Array
 	 *    @param	int			            $include			[=0] Removed or 1=Keep only
 	 *    @param	string					$morecss			More CSS
-	 *    @return	string
+	 *    @return	string|array
 	 *    @see select_categories()
 	 */
 	public function select_all_categories($type, $selected = '', $htmlname = "parent", $maxlength = 64, $markafterid = 0, $outputmode = 0, $include = 0, $morecss = '')