diff --git a/build.gradle b/build.gradle
index ddff43d1e0..1295e2d071 100644
--- a/build.gradle
+++ b/build.gradle
@@ -106,7 +106,7 @@ subprojects { subproject ->
 		hibernateVersion = '5.2.10.Final'
 		hsqldbVersion = '2.4.0'
 		h2Version = '1.4.196'
-		jackson2Version = '2.9.1'
+		jackson2Version = '2.9.4'
 		javaxActivationVersion = '1.1.1'
 		javaxMailVersion = '1.6.0'
 		jedisVersion = '2.9.0'
diff --git a/spring-integration-core/src/main/java/org/springframework/integration/dispatcher/AggregateMessageDeliveryException.java b/spring-integration-core/src/main/java/org/springframework/integration/dispatcher/AggregateMessageDeliveryException.java
index 9b2f24a092..8756719431 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/dispatcher/AggregateMessageDeliveryException.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/dispatcher/AggregateMessageDeliveryException.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,7 +16,7 @@
 
 package org.springframework.integration.dispatcher;
 
-import java.util.Collections;
+import java.util.ArrayList;
 import java.util.List;
 
 import org.springframework.messaging.Message;
@@ -28,6 +28,8 @@ import org.springframework.util.StringUtils;
  * that may try multiple handler invocations within a single dispatch operation.
  *
  * @author Mark Fisher
+ * @author Artem Bilan
+ *
  * @since 1.0.3
  */
 @SuppressWarnings("serial")
@@ -38,13 +40,18 @@ public class AggregateMessageDeliveryException extends MessageDeliveryException
 
 	public AggregateMessageDeliveryException(Message<?> undeliveredMessage,
 			String description, List<? extends Exception> aggregatedExceptions) {
+
 		super(undeliveredMessage, description);
 		this.initCause(aggregatedExceptions.get(0));
-		this.aggregatedExceptions = aggregatedExceptions;
+		this.aggregatedExceptions = new ArrayList<Exception>(aggregatedExceptions);
 	}
 
+	/**
+	 * Obtain a list aggregated target exceptions.
+	 * @return the list of target exceptions
+	 */
 	public List<? extends Exception> getAggregatedExceptions() {
-		return Collections.unmodifiableList(this.aggregatedExceptions);
+		return new ArrayList<Exception>(this.aggregatedExceptions);
 	}
 
 	@Override
diff --git a/spring-integration-core/src/main/java/org/springframework/integration/store/MessageGroupMetadata.java b/spring-integration-core/src/main/java/org/springframework/integration/store/MessageGroupMetadata.java
index 2ea8394f3b..1930b98a6b 100644
--- a/spring-integration-core/src/main/java/org/springframework/integration/store/MessageGroupMetadata.java
+++ b/spring-integration-core/src/main/java/org/springframework/integration/store/MessageGroupMetadata.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,6 @@
 package org.springframework.integration.store;
 
 import java.io.Serializable;
-import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
@@ -92,8 +91,13 @@ public class MessageGroupMetadata implements Serializable {
 		return null;
 	}
 
+	/**
+	 * Obtain a {@link LinkedList} copy of the {@link #messageIds}
+	 * stored in the group.
+	 * @return the list of messages ids stored in the group
+	 */
 	public List<UUID> getMessageIds() {
-		return Collections.unmodifiableList(this.messageIds);
+		return new LinkedList<UUID>(this.messageIds);
 	}
 
 	void complete() {