diff --git a/build.gradle b/build.gradle
index bfcf293..a849dd1 100644
--- a/build.gradle
+++ b/build.gradle
@@ -10,7 +10,7 @@ repositories {
 }
 
 group = "org.embulk"
-version = "0.3.3-SNAPSHOT"
+version = "0.4.0-SNAPSHOT"
 description "Almost Ruby-compatible date-time processor for Embulk and Embulk plugins"
 
 configurations {