diff --git a/src/Oro/Bundle/WorkflowBundle/Async/Topic/AbstractWorkflowTransitionTriggerTopic.php b/src/Oro/Bundle/WorkflowBundle/Async/Topic/AbstractWorkflowTransitionTriggerTopic.php
index a7cb5bf6492..d45cce1077c 100644
--- a/src/Oro/Bundle/WorkflowBundle/Async/Topic/AbstractWorkflowTransitionTriggerTopic.php
+++ b/src/Oro/Bundle/WorkflowBundle/Async/Topic/AbstractWorkflowTransitionTriggerTopic.php
@@ -22,6 +22,6 @@ public function configureMessageBody(OptionsResolver $resolver): void
 
         $resolver
             ->setRequired(TransitionTriggerMessage::MAIN_ENTITY)
-            ->setAllowedTypes(TransitionTriggerMessage::MAIN_ENTITY, ['int', 'string', 'array']);
+            ->setAllowedTypes(TransitionTriggerMessage::MAIN_ENTITY, ['int', 'string', 'array', 'null']);
     }
 }