diff --git a/unconstrained.cabal b/unconstrained.cabal
--- a/unconstrained.cabal
+++ b/unconstrained.cabal
@@ -1,5 +1,5 @@
 name:                unconstrained
-version:             0.1.0.0
+version:             0.1.0.1
 synopsis:            Null constraint
 -- description:         
 license:             BSD3
@@ -14,6 +14,7 @@
 library
   exposed-modules:     Unconstrained
   -- other-modules:       
+  default-extensions:  PolyKinds
   other-extensions:    FlexibleInstances
   build-depends:       base >=4 && <5
   hs-source-dirs:      src