diff --git a/CHANGES.md b/CHANGES.md
index 690c560..c4d78b8 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,6 +1,12 @@
 Nirum changelog
 ===============
 
+Version 0.3.1
+-------------
+
+To be released.
+
+
 Version 0.3.0
 -------------
 
diff --git a/README.md b/README.md
index 84563d5..b172252 100644
--- a/README.md
+++ b/README.md
@@ -93,7 +93,7 @@ For more infomration, use `--help` option:
     Nirum: The IDL compiler and RPC/distributed object framework
 
     Usage: nirum [-v|--version] (-o|--output-dir DIR) (-t|--target TARGET) DIR
-      Nirum compiler 0.3.0
+      Nirum compiler 0.3.1
 
     Available options:
       -h,--help                Show this help text
diff --git a/docs/tutorial.md b/docs/tutorial.md
index 8367aca..6e503e1 100644
--- a/docs/tutorial.md
+++ b/docs/tutorial.md
@@ -135,7 +135,7 @@ a command-line prompt and it's consistent within this tutorial):
 
 ~~~~~~~~ sh
 $ nirum -v
-0.3.0
+0.3.1
 ~~~~~~~~
 
 [official releases page]: https://github.com/spoqa/nirum/releases
diff --git a/package.yaml b/package.yaml
index 33f1cd2..0f7c1fa 100644
--- a/package.yaml
+++ b/package.yaml
@@ -2,7 +2,7 @@ name: nirum
 version:
   # CHECK: When the version is bumped, update the docs and README.md file as
   # well.  Check using `git grep -E '[0-9]+\.[0-9]+\.[0-9]+' '*.md'` command.
-  '0.3.0'
+  '0.3.1'
 synopsis: ! >
   IDL compiler and RPC/distributed object framework for
   microservices
diff --git a/test/Nirum/VersionSpec.hs b/test/Nirum/VersionSpec.hs
index 8d8e7b7..7d35481 100644
--- a/test/Nirum/VersionSpec.hs
+++ b/test/Nirum/VersionSpec.hs
@@ -17,7 +17,7 @@ spec = do
             version `shouldSatisfy` SV.isDevelopment
         it "is the proper version" $
             -- is it a necessary test?
-            version `shouldBe` SV.version 0 3 0 [] []
+            version `shouldBe` SV.version 0 3 1 [] []
     describe "versionText" $ do
         it "is equivalent to version" $
             versionText `shouldBe` SV.toText version