diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 95b5ef67501..7f5c3c351c7 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -3102,7 +3102,7 @@ function img_picto($titlealt, $picto, $moreatt = '', $pictoisfullpath = false, $
 				$fakey = 'fa-'.$arrayconvpictotofa[$pictowithouttext];
 			}
 			elseif ($pictowithouttext == 'switch_on') {
-				$morecss = 'font-status4';
+				$morecss .= ($morecss ? ' ' : '').'font-status4';
 				$fakey = 'fa-'.$arrayconvpictotofa[$pictowithouttext];
 			}
 			elseif ($pictowithouttext == 'off') {