diff --git a/chapter12/src/main/java/nia/chapter12/HttpRequestHandler.java b/chapter12/src/main/java/nia/chapter12/HttpRequestHandler.java
index b781cde0..cd67de6f 100644
--- a/chapter12/src/main/java/nia/chapter12/HttpRequestHandler.java
+++ b/chapter12/src/main/java/nia/chapter12/HttpRequestHandler.java
@@ -51,7 +51,7 @@ public void channelRead0(ChannelHandlerContext ctx,
                 request.getProtocolVersion(), HttpResponseStatus.OK);
             response.headers().set(
                 HttpHeaders.Names.CONTENT_TYPE,
-                "text/plain; charset=UTF-8");
+                "text/html; charset=UTF-8");
             boolean keepAlive = HttpHeaders.isKeepAlive(request);
             if (keepAlive) {
                 response.headers().set(