diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index 63d7f749be7..6b69427eacd 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -4525,7 +4525,7 @@ function dol_textishtml($msg,$option=0)
 }
 
 /**
- *  Concat 2 descriptions (second one after first one with a new line separator if required)
+ *  Concat 2 descriptions with a new line between them (second operand after first one with appropriate new line separator)
  *  text1 html + text2 html => text1 + '<br>' + text2
  *  text1 html + text2 txt  => text1 + '<br>' + dol_nl2br(text2)
  *  text1 txt  + text2 html => dol_nl2br(text1) + '<br>' + text2
diff --git a/htdocs/core/triggers/interface_50_modAgenda_ActionsAuto.class.php b/htdocs/core/triggers/interface_50_modAgenda_ActionsAuto.class.php
index 40a06f11648..53908142e03 100644
--- a/htdocs/core/triggers/interface_50_modAgenda_ActionsAuto.class.php
+++ b/htdocs/core/triggers/interface_50_modAgenda_ActionsAuto.class.php
@@ -683,7 +683,7 @@ class InterfaceActionsAuto extends DolibarrTriggers
 			$attachs=$_SESSION['listofnames'];
 			if ($attachs && strpos($action,'SENTBYMAIL'))
 			{
-				 $object->actionmsg.="\n".$langs->transnoentities("AttachedFiles").': '.$attachs;
+                $object->actionmsg=dol_concatdesc($object->actionmsg, "\n".$langs->transnoentities("AttachedFiles").': '.$attachs);
 			}
 		}