diff --git a/spring-web/src/main/java/org/springframework/http/client/Netty4ClientHttpRequest.java b/spring-web/src/main/java/org/springframework/http/client/Netty4ClientHttpRequest.java
index 24e773aadaf..7f7e32c9d5b 100644
--- a/spring-web/src/main/java/org/springframework/http/client/Netty4ClientHttpRequest.java
+++ b/spring-web/src/main/java/org/springframework/http/client/Netty4ClientHttpRequest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -137,14 +137,14 @@ class Netty4ClientHttpRequest extends AbstractAsyncClientHttpRequest implements
 				HttpVersion.HTTP_1_1, nettyMethod, path, this.body.buffer());
 
 		nettyRequest.headers().set(HttpHeaders.HOST, this.uri.getHost());
-		if (this.body.buffer().readableBytes() > 0) {
-			nettyRequest.headers().set(HttpHeaders.CONTENT_LENGTH, this.body.buffer().readableBytes());
-		}
 		nettyRequest.headers().set(HttpHeaders.CONNECTION, "close");
-
 		for (Map.Entry<String, List<String>> entry : headers.entrySet()) {
 			nettyRequest.headers().add(entry.getKey(), entry.getValue());
 		}
+		if (!nettyRequest.headers().contains(HttpHeaders.CONTENT_LENGTH)
+				&& this.body.buffer().readableBytes() > 0) {
+			nettyRequest.headers().set(HttpHeaders.CONTENT_LENGTH, this.body.buffer().readableBytes());
+		}
 
 		return nettyRequest;
 	}
diff --git a/spring-web/src/test/java/org/springframework/web/client/AbstractMockWebServerTestCase.java b/spring-web/src/test/java/org/springframework/web/client/AbstractMockWebServerTestCase.java
index 4c58bbb7aa2..4f0bf95b758 100644
--- a/spring-web/src/test/java/org/springframework/web/client/AbstractMockWebServerTestCase.java
+++ b/spring-web/src/test/java/org/springframework/web/client/AbstractMockWebServerTestCase.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -85,6 +85,7 @@ public class AbstractMockWebServerTestCase {
 	private MockResponse postRequest(RecordedRequest request, String expectedRequestContent,
 			String location, String contentType, byte[] responseBody) {
 
+		assertEquals(1, request.getHeaders().values("Content-Length").size());
 		assertTrue("Invalid request content-length",
 				Integer.parseInt(request.getHeader("Content-Length")) > 0);
 		String requestContentType = request.getHeader("Content-Type");