diff --git a/messagepack.html.markdown b/messagepack.html.markdown
index 9291fffc..9234332f 100644
--- a/messagepack.html.markdown
+++ b/messagepack.html.markdown
@@ -1,5 +1,6 @@
 ---
-language: messagepack
+category: tool
+tool: messagepack
 filename: learnmessagepack.mpac
 contributors:
   - ["Gabriel Chuan", "https://github.com/gczh"]
@@ -168,4 +169,4 @@ function mytipeDecode(data) {
 # References
 
 - [MessagePack](http://msgpack.org/index.html)
-- [MsgPack vs. JSON: Cut your client-server exchange traffic by 50% with one line of code](http://indiegamr.com/cut-your-data-exchange-traffic-by-up-to-50-with-one-line-of-code-msgpack-vs-json/)
\ No newline at end of file
+- [MsgPack vs. JSON: Cut your client-server exchange traffic by 50% with one line of code](http://indiegamr.com/cut-your-data-exchange-traffic-by-up-to-50-with-one-line-of-code-msgpack-vs-json/)