diff --git a/htdocs/core/class/html.formfile.class.php b/htdocs/core/class/html.formfile.class.php
index f932e739ad1..c41c61be536 100644
--- a/htdocs/core/class/html.formfile.class.php
+++ b/htdocs/core/class/html.formfile.class.php
@@ -79,9 +79,10 @@ class FormFile
 	 *	@param	string		$sectiondir		If upload must be done inside a particular directory (if sectiondir defined, sectionid must not be)
 	 *  @param  int         $usewithoutform 0=Default, 1=Disable <form> and style to use in existing area
 	 *  @param	int			$capture		1=Add tag capture="capture" to force use of micro or video recording to generate file. When setting this to 1, you must also provide a value for $accept.
+	 *  @param	int			$disablemulti	0=Default, 1=Disable multiple file upload
 	 * 	@return	int							<0 if KO, >0 if OK
 	 */
-	public function form_attach_new_file($url, $title = '', $addcancel = 0, $sectionid = 0, $perm = 1, $size = 50, $object = '', $options = '', $useajax = 1, $savingdocmask = '', $linkfiles = 1, $htmlname = 'formuserfile', $accept = '', $sectiondir = '', $usewithoutform = 0, $capture = 0)
+	public function form_attach_new_file($url, $title = '', $addcancel = 0, $sectionid = 0, $perm = 1, $size = 50, $object = '', $options = '', $useajax = 1, $savingdocmask = '', $linkfiles = 1, $htmlname = 'formuserfile', $accept = '', $sectiondir = '', $usewithoutform = 0, $capture = 0, $disablemulti = 0)
 	{
 		// phpcs:enable
 		global $conf, $langs, $hookmanager;
@@ -170,7 +171,7 @@ class FormFile
 
 			$out .= '<input class="flat minwidth400 maxwidth200onsmartphone" type="file"';
 			//$out .= ((!empty($conf->global->MAIN_DISABLE_MULTIPLE_FILEUPLOAD) || $conf->browser->layout != 'classic') ? ' name="userfile"' : ' name="userfile[]" multiple');
-			$out .= ((!empty($conf->global->MAIN_DISABLE_MULTIPLE_FILEUPLOAD)) ? ' name="userfile"' : ' name="userfile[]" multiple');
+			$out .= ((!empty($conf->global->MAIN_DISABLE_MULTIPLE_FILEUPLOAD) || $disablemulti) ? ' name="userfile"' : ' name="userfile[]" multiple');
 			$out .= (empty($conf->global->MAIN_UPLOAD_DOC) || empty($perm) ? ' disabled' : '');
 			$out .= (!empty($accept) ? ' accept="'.$accept.'"' : ' accept=""');
 			$out .= (!empty($capture) ? ' capture="capture"' : '');