diff --git a/History.md b/History.md
index 04be8f6..7215c8f 100644
--- a/History.md
+++ b/History.md
@@ -1,10 +1,16 @@
 
+0.12.0 / 2014-09-20
+==================
+
+ * add this.assert()
+ * use content-disposition
+ 
 0.11.0 / 2014-09-08
 ==================
 
  * fix app.use() assertion #337
  * bump a lot of dependencies
- 
+
 0.10.0 / 2014-08-12
 ==================
 
diff --git a/package.json b/package.json
index c10b337..910eec6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "koa",
-  "version": "0.11.0",
+  "version": "0.12.0",
   "description": "Koa web app framework",
   "main": "lib/application.js",
   "scripts": {