diff --git a/src/Models/Message.php b/src/Models/Message.php
index 4498b7a..2cc792d 100644
--- a/src/Models/Message.php
+++ b/src/Models/Message.php
@@ -48,7 +48,7 @@ public function participation()
 
     public function getSenderAttribute()
     {
-        $participantModel = $this->participation->messageable;
+        $participantModel = $this->participation?->messageable;
 
         if (!isset($participantModel)) {
             return null;