diff --git a/package.json b/package.json
index 0b8dce3..c926eba 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "interface-stream-muxer",
-  "version": "0.3.1",
+  "version": "0.4.0",
   "description": "A test suite and interface you can use to implement a stream muxer.",
   "main": "lib/index.js",
   "jsnext:main": "src/index.js",