diff --git a/build.sbt b/build.sbt
index c76f738e..6b3a1fc6 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,6 +1,6 @@
 organization in ThisBuild := "org.reactivestreams"
 
-version in ThisBuild := "0.3"
+version in ThisBuild := "0.4-SNAPSHOT"
 
 scalaVersion in ThisBuild := "2.10.3"