diff --git a/envy.cabal b/envy.cabal
--- a/envy.cabal
+++ b/envy.cabal
@@ -1,5 +1,5 @@
 name:                envy
-version:             1.3.0.2
+version:             1.5.0.0
 synopsis:            An environmentally friendly way to deal with environment variables
 license:             BSD3
 license-file:        LICENSE
@@ -37,10 +37,10 @@
     build-depends:      base
                       , bytestring
                       , envy
-                      , hspec                >= 2.2 && < 2.5
+                      , hspec
                       , mtl
-                      , quickcheck-instances == 0.3.*
-                      , QuickCheck           >= 2.8 && < 2.10
+                      , quickcheck-instances
+                      , QuickCheck
                       , text
                       , time
                       , transformers
diff --git a/src/System/Envy.hs b/src/System/Envy.hs
--- a/src/System/Envy.hs
+++ b/src/System/Envy.hs
@@ -13,7 +13,7 @@
 -- |
 -- Module      : System.Envy
 -- Copyright   : (c) David Johnson 2015
--- Maintainer  : djohnson.m@ngmail.com
+-- Maintainer  : djohnson.m@gmail.com
 -- Stability   : experimental
 -- Portability : POSIX
 --
@@ -49,6 +49,7 @@
        , ToEnv   (..)
        , Var     (..)
        , EnvList
+       , Parser  (..)
         -- * Functions
        , decodeEnv
        , decode
@@ -67,6 +68,7 @@
        , Option (..)
        , runEnv
        , gFromEnvCustom
+       , runParser
        ) where
 ------------------------------------------------------------------------------
 import           Control.Applicative
@@ -286,6 +288,11 @@
 instance Var Word32 where toVar = show; fromVar = readMaybe
 instance Var Word64 where toVar = show; fromVar = readMaybe
 instance Var String where toVar = id; fromVar = Just
+instance Var () where toVar = const "()"; fromVar = const $ Just ()
+instance Var a => Var (Maybe a) where
+  toVar = maybe "" toVar
+  fromVar "" = Nothing
+  fromVar  s = Just <$> fromVar s
 
 ------------------------------------------------------------------------------
 -- | Environment retrieval with failure info
diff --git a/tests/Main.hs b/tests/Main.hs
--- a/tests/Main.hs
+++ b/tests/Main.hs
@@ -105,6 +105,8 @@
      \(x :: LT.Text) -> Just x == fromVar (toVar x)
     it "Text Var isomorphism" $ property $
      \(x :: T.Text) -> Just x == fromVar (toVar x)
+    it "() Var isomorphism" $ property $
+     \(x :: ()) -> Just x == fromVar (toVar x)
   describe "Can set to and from environment" $
     it "Isomorphism through setEnvironment['] and decodeEnv" $ property $
       \(pgConf::PGConfig) -> monadicIO $ do