diff --git a/spring-amqp/src/main/java/org/springframework/amqp/support/converter/MessagingMessageConverter.java b/spring-amqp/src/main/java/org/springframework/amqp/support/converter/MessagingMessageConverter.java
index 5069eaa8..50fd72c4 100644
--- a/spring-amqp/src/main/java/org/springframework/amqp/support/converter/MessagingMessageConverter.java
+++ b/spring-amqp/src/main/java/org/springframework/amqp/support/converter/MessagingMessageConverter.java
@@ -108,9 +108,9 @@ public class MessagingMessageConverter implements MessageConverter, Initializing
 				input.getPayload(), messageProperties);
 		// Default previous behavior of mapper wins for backwards compatibility.
 		if (!Boolean.TRUE.equals(input.getHeaders().get(AmqpHeaders.CONTENT_TYPE_CONVERTER_WINS))) {
-			String contentType = input.getHeaders().get(MessageHeaders.CONTENT_TYPE, String.class);
+			Object contentType = input.getHeaders().get(MessageHeaders.CONTENT_TYPE);
 			if (contentType != null) {
-				messageProperties.setContentType(contentType);
+				messageProperties.setContentType(contentType.toString());
 			}
 		}
 		return amqpMessage;
diff --git a/spring-rabbit/src/test/java/org/springframework/amqp/rabbit/annotation/ContentTypeDelegatingMessageConverterIntegrationTests.java b/spring-rabbit/src/test/java/org/springframework/amqp/rabbit/annotation/ContentTypeDelegatingMessageConverterIntegrationTests.java
index 4ca1a022..ab30e0f7 100644
--- a/spring-rabbit/src/test/java/org/springframework/amqp/rabbit/annotation/ContentTypeDelegatingMessageConverterIntegrationTests.java
+++ b/spring-rabbit/src/test/java/org/springframework/amqp/rabbit/annotation/ContentTypeDelegatingMessageConverterIntegrationTests.java
@@ -47,6 +47,7 @@ import org.springframework.messaging.MessageHeaders;
 import org.springframework.messaging.handler.annotation.SendTo;
 import org.springframework.messaging.support.MessageBuilder;
 import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.util.MimeType;
 
 /**
  * @author Gary Russell
@@ -172,7 +173,7 @@ public class ContentTypeDelegatingMessageConverterIntegrationTests {
 		@SendTo("#{@queue2.name}")
 		public org.springframework.messaging.Message<String> listen1(String in) {
 			MessageBuilder<String> builder = MessageBuilder.withPayload(in)
-					.setHeader(MessageHeaders.CONTENT_TYPE, "baz/qux");
+					.setHeader(MessageHeaders.CONTENT_TYPE, MimeType.valueOf("baz/qux"));
 			if ("bar".equals(in)) {
 				builder.setHeader(AmqpHeaders.CONTENT_TYPE_CONVERTER_WINS, true);
 			}