diff --git a/org.springframework.integration/src/main/java/org/springframework/integration/message/MessageBuilder.java b/org.springframework.integration/src/main/java/org/springframework/integration/message/MessageBuilder.java
index 71cdcab15d..ab3b3ae6a7 100644
--- a/org.springframework.integration/src/main/java/org/springframework/integration/message/MessageBuilder.java
+++ b/org.springframework.integration/src/main/java/org/springframework/integration/message/MessageBuilder.java
@@ -20,6 +20,7 @@ import java.util.Date;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
+import java.util.UUID;
 
 import org.springframework.integration.core.Message;
 import org.springframework.integration.core.MessageChannel;
@@ -87,6 +88,7 @@ public final class MessageBuilder<T> {
 	 */
 	public MessageBuilder<T> setHeader(String headerName, Object headerValue) {
 		if (StringUtils.hasLength(headerName)) {
+			this.verifyType(headerName, headerValue);
 			this.modified = true;
 			if (headerValue == null) {
 				this.headers.remove(headerName);
@@ -201,4 +203,32 @@ public final class MessageBuilder<T> {
 		return new GenericMessage<T>(this.payload, this.headers);
 	}
 
+	private void verifyType(String headerName, Object headerValue) {
+		if (headerName != null && headerValue != null) {
+			if (MessageHeaders.ID.equals(headerName)) {
+				Assert.isTrue(headerValue instanceof UUID,
+						"The '" + headerName + "' header value must be a UUID.");
+			}
+			else if (MessageHeaders.TIMESTAMP.equals(headerName)) {
+				Assert.isTrue(headerValue instanceof Long,
+						"The '" + headerName + "' header value must be a Long.");
+			}
+			else if (MessageHeaders.EXPIRATION_DATE.equals(headerName)) {
+				Assert.isTrue(headerValue instanceof Date || headerValue instanceof Long,
+						"The '" + headerName + "' header value must be a Date or Long.");
+			}
+			else if (MessageHeaders.ERROR_CHANNEL.equals(headerName) ||
+					MessageHeaders.REPLY_CHANNEL.endsWith(headerName)) {
+				Assert.isTrue(headerValue instanceof MessageChannel ||
+						headerValue instanceof String,
+						"The '" + headerName + "' header value must be a MessageChannel or String.");
+			}
+			else if (MessageHeaders.SEQUENCE_NUMBER.equals(headerName) ||
+					MessageHeaders.SEQUENCE_SIZE.equals(headerName)) {
+				Assert.isTrue(Integer.class.isAssignableFrom(headerValue.getClass()),
+						"The '" + headerName + "' header value must be an Integer.");
+			}
+		}
+	}
+
 }
diff --git a/org.springframework.integration/src/test/java/org/springframework/integration/aggregator/AggregatorEndpointTests.java b/org.springframework.integration/src/test/java/org/springframework/integration/aggregator/AggregatorEndpointTests.java
index 8ba28e31f3..107df2aab0 100644
--- a/org.springframework.integration/src/test/java/org/springframework/integration/aggregator/AggregatorEndpointTests.java
+++ b/org.springframework.integration/src/test/java/org/springframework/integration/aggregator/AggregatorEndpointTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -16,17 +16,22 @@
 
 package org.springframework.integration.aggregator;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
+import java.util.UUID;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
-import org.junit.Ignore;
-import static org.junit.Assert.*;
+
 import org.springframework.core.task.SimpleAsyncTaskExecutor;
 import org.springframework.core.task.TaskExecutor;
 import org.springframework.integration.channel.QueueChannel;
@@ -37,7 +42,6 @@ import org.springframework.integration.message.MessageBuilder;
 import org.springframework.integration.message.MessageHandlingException;
 import org.springframework.integration.message.StringMessage;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
-import static org.hamcrest.CoreMatchers.is;
 
 /**
  * @author Mark Fisher
@@ -81,9 +85,10 @@ public class AggregatorEndpointTests {
 	@Test
 	public void testCompleteGroupWithinTimeoutWithSameId() throws InterruptedException {
 		QueueChannel replyChannel = new QueueChannel();
-		Message<?> message1 = createMessage("123", "ABC", 3, 1, replyChannel, "ID#1");
-		Message<?> message2 = createMessage("456", "ABC", 3, 2, replyChannel, "ID#1");
-		Message<?> message3 = createMessage("789", "ABC", 3, 3, replyChannel, "ID#1");
+		UUID id = UUID.randomUUID();
+		Message<?> message1 = createMessage("123", "ABC", 3, 1, replyChannel, id);
+		Message<?> message2 = createMessage("456", "ABC", 3, 2, replyChannel, id);
+		Message<?> message3 = createMessage("789", "ABC", 3, 3, replyChannel, id);
 		CountDownLatch latch = new CountDownLatch(3);
 		//for testing the duplication scenario, the messages must be processed synchronously
 		new AggregatorTestTask(this.aggregator, message1, latch).run();
@@ -258,7 +263,7 @@ public class AggregatorEndpointTests {
 
 
 	private static Message<?> createMessage(String payload, Object correlationId,
-                                            int sequenceSize, int sequenceNumber, MessageChannel replyChannel, String predefinedId) {
+                                            int sequenceSize, int sequenceNumber, MessageChannel replyChannel, UUID predefinedId) {
         MessageBuilder<String> builder = MessageBuilder.withPayload(payload)
                 .setCorrelationId(correlationId)
                 .setSequenceSize(sequenceSize)