diff --git a/Data/Type/Monomorphic.hs b/Data/Type/Monomorphic.hs
--- a/Data/Type/Monomorphic.hs
+++ b/Data/Type/Monomorphic.hs
@@ -1,6 +1,6 @@
 {-# LANGUAGE DataKinds, ExistentialQuantification, FlexibleContexts, GADTs #-}
-{-# LANGUAGE PolyKinds, RankNTypes, TypeFamilies, TypeOperators            #-}
-{-# LANGUAGE UndecidableInstances                                          #-}
+{-# LANGUAGE ImpredicativeTypes, PolyKinds, RankNTypes, TypeFamilies       #-}
+{-# LANGUAGE TypeOperators, UndecidableInstances                           #-}
 module Data.Type.Monomorphic ( Monomorphic (..), Monomorphicable(..)
                    , demote', demoteComposed, monomorphicCompose
                    , withPolymorhic, liftPoly, viaPoly, (:.:)(..)
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,5 +1,6 @@
 The `monomorphic` library
 ==========================
+[![Build Status](https://travis-ci.org/konn/monomorphic.svg)](https://travis-ci.org/konn/monomorphic)
 
 What is this?
 -------------
diff --git a/monomorphic.cabal b/monomorphic.cabal
--- a/monomorphic.cabal
+++ b/monomorphic.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                monomorphic
-version:             0.0.3.0
+version:             0.0.3.1
 synopsis:            Library to convert polymorphic datatypes to/from its monomorphic represetation
 description:         This library provides the type-class and functions to convert between polymorphic data-types and its monomorphic representation type, such as length-indexed vectors, singletons for type-level natural numbers, etc.
 homepage:            https://github.com/konn/monomorphic