diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 04e1b9a05549a..d2609495d490c 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -14605,7 +14605,7 @@ function show_actions_messaging($conf, $langs, $db, $filterobj, $objcon = null,
 
 
 			$out .= '<!-- timeline item -->'."\n";
-			$out .= '<li class="timeline-code-'.strtolower($actionstatic->code).'">';
+			$out .= '<li class="timeline-code-'.(!empty($actionstatic->code) ? strtolower($actionstatic->code) : "none").'">';
 
 			//$timelineicon = getTimelineIcon($actionstatic, $histo, $key);
 			$typeicon = $actionstatic->getTypePicto('pictofixedwidth timeline-icon-not-applicble', $labeltype);