diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,3 +6,10 @@
 ## 0.0.2
 ### Added
 * Add `hask` to read from MonadReaer
+
+## 0.0.3
+### Added
+* Export typefamily `Contains`
+* Export `hask`
+### Updated
+* Make it compilable on base < 4.8
diff --git a/hset.cabal b/hset.cabal
--- a/hset.cabal
+++ b/hset.cabal
@@ -1,5 +1,5 @@
 name:                hset
-version:             0.0.2
+version:             0.0.3
 synopsis:            Primitive heterogenous read-only set
 license:             BSD3
 license-file:        LICENSE
@@ -25,7 +25,8 @@
   build-depends:       base >=4.6 && < 5
                      , mtl
 
-  default-extensions: ConstraintKinds
+  default-extensions: CPP
+                    , ConstraintKinds
                     , DataKinds
                     , FlexibleContexts
                     , FlexibleInstances
diff --git a/src/Data/HSet.hs b/src/Data/HSet.hs
--- a/src/Data/HSet.hs
+++ b/src/Data/HSet.hs
@@ -1,10 +1,15 @@
 module Data.HSet
        ( HSet(..)
        , HGet(..)
+       , Contains
+       , hask
        ) where
 
 import Control.Monad.Reader
 import Data.HSet.TypeLevel
+#if !(MIN_VERSION_base(4, 8, 0))
+import Control.Applicative
+#endif
 
 -- | Heterogeneous set (list) of elements with unique types. Usefull
 -- with MonadReader