diff --git a/examples/hawkbit-device-simulator/src/main/java/org/eclipse/hawkbit/simulator/amqp/SpSenderService.java b/examples/hawkbit-device-simulator/src/main/java/org/eclipse/hawkbit/simulator/amqp/SpSenderService.java
index 1ced8c2fd..f384347c6 100644
--- a/examples/hawkbit-device-simulator/src/main/java/org/eclipse/hawkbit/simulator/amqp/SpSenderService.java
+++ b/examples/hawkbit-device-simulator/src/main/java/org/eclipse/hawkbit/simulator/amqp/SpSenderService.java
@@ -206,7 +206,7 @@ public class SpSenderService extends SenderService {
         headers.put(MessageHeaderKey.TENANT, cacheValue.getTenant());
         headers.put(MessageHeaderKey.TOPIC, EventTopic.UPDATE_ACTION_STATUS.name());
         headers.put(MessageHeaderKey.CONTENT_TYPE, MessageProperties.CONTENT_TYPE_JSON);
-        actionUpdateStatus.getMessage().addAll(updateResultMessages);
+        actionUpdateStatus.addMessage(updateResultMessages);
         actionUpdateStatus.setActionId(cacheValue.getActionId());
         return convertMessage(actionUpdateStatus, messageProperties);
     }
diff --git a/hawkbit-dmf-api/src/main/java/org/eclipse/hawkbit/dmf/json/model/ActionUpdateStatus.java b/hawkbit-dmf-api/src/main/java/org/eclipse/hawkbit/dmf/json/model/ActionUpdateStatus.java
index 2262cab96..652039e35 100644
--- a/hawkbit-dmf-api/src/main/java/org/eclipse/hawkbit/dmf/json/model/ActionUpdateStatus.java
+++ b/hawkbit-dmf-api/src/main/java/org/eclipse/hawkbit/dmf/json/model/ActionUpdateStatus.java
@@ -9,6 +9,7 @@
 package org.eclipse.hawkbit.dmf.json.model;
 
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 
@@ -72,4 +73,12 @@ public class ActionUpdateStatus {
         return this.message.add(message);
     }
 
+    public boolean addMessage(final Collection<String> messages) {
+        if (this.message == null) {
+            this.message = new ArrayList<>();
+        }
+
+        return this.message.addAll(messages);
+    }
+
 }