diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2014, Matvey Aksenov
+Copyright (c) 2014-2015, Matvey Aksenov
 
 All rights reserved.
 
diff --git a/envparse.cabal b/envparse.cabal
--- a/envparse.cabal
+++ b/envparse.cabal
@@ -1,5 +1,5 @@
 name:                envparse
-version:             0.2.1
+version:             0.2.2
 synopsis:            Parse environment variables
 description:
   Here's a simple example of a program that uses @envparse@'s parser:
@@ -49,7 +49,7 @@
 license-file:        LICENSE
 author:              Matvey Aksenov
 maintainer:          matvey.aksenov@gmail.com
-copyright:           2014 Matvey Aksenov
+copyright:           2015 Matvey Aksenov
 category:            System
 build-type:          Simple
 cabal-version:       >= 1.10
@@ -65,7 +65,7 @@
 source-repository this
   type:     git
   location: https://github.com/supki/envparse
-  tag:      0.2.1
+  tag:      0.2.2
 
 library
   default-language:
@@ -99,3 +99,5 @@
     test
   main-is:
     Spec.hs
+  ghc-options:
+    -Wall
diff --git a/src/Env.hs b/src/Env.hs
--- a/src/Env.hs
+++ b/src/Env.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE Safe #-}
 -- | Here's a simple example of a program that uses @envparse@'s parser:
 --
@@ -64,6 +65,7 @@
   , Flag
   , HasHelp
   , help
+  , helpDoc
   -- * Re-exports
   -- $re-exports
   , pure, (<$>), (<*>), (*>), (<*), optional
@@ -79,12 +81,15 @@
 import           Control.Applicative
 import           Control.Monad ((>=>), (<=<))
 import           Data.Foldable (asum)
-import           Data.Monoid (Monoid(..), (<>))
+#if __GLASGOW_HASKELL__ < 710
+import           Data.Monoid (Monoid(..))
+#endif
+import           Data.Monoid ((<>))
 import           System.Environment (getEnvironment)
 import           System.Exit (exitFailure)
 import qualified System.IO as IO
 
-import           Env.Help (helpDoc)
+import           Env.Help (helpInfo, helpDoc)
 import           Env.Parse
 
 -- $re-exports
@@ -116,7 +121,7 @@
 
 -- | Try to parse a pure environment
 parsePure :: Mod Info a -> Parser a -> [(String, String)] -> Either String a
-parsePure (Mod f) p = mapLeft (helpDoc (f defaultInfo) p) . static p
+parsePure (Mod f) p = mapLeft (helpInfo (f defaultInfo) p) . static p
 
 mapLeft :: (a -> b) -> Either a t -> Either b t
 mapLeft f = either (Left . f) Right
diff --git a/src/Env/Free.hs b/src/Env/Free.hs
--- a/src/Env/Free.hs
+++ b/src/Env/Free.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE RankNTypes #-}
 {-# LANGUAGE ScopedTypeVariables #-}
@@ -12,8 +13,13 @@
   , inspect
   ) where
 
-import Control.Applicative (Applicative(..), Alternative(..))
+#if __GLASGOW_HASKELL__ < 710
+import Control.Applicative (Applicative(..))
+#endif
+import Control.Applicative (Alternative(..))
+#if __GLASGOW_HASKELL__ < 710
 import Data.Monoid (Monoid(..))
+#endif
 
 
 data Alt f a where
diff --git a/src/Env/Help.hs b/src/Env/Help.hs
--- a/src/Env/Help.hs
+++ b/src/Env/Help.hs
@@ -1,28 +1,32 @@
 {-# LANGUAGE NamedFieldPuns #-}
 module Env.Help
-  ( helpDoc
+  ( helpInfo
+  , helpDoc
   ) where
 
 import qualified Data.List as List
 import qualified Data.Map as Map
 import           Data.Maybe (catMaybes)
-import           Data.Monoid ((<>))
 import           Data.Ord (comparing)
 
 import           Env.Free
 import           Env.Parse
 
 
-helpDoc :: Info a -> Parser b -> [Error] -> String
-helpDoc Info { infoHeader, infoDesc, infoFooter } p fs =
-  List.intercalate "\n\n" . catMaybes $
+helpInfo :: Info a -> Parser b -> [Error] -> String
+helpInfo Info { infoHeader, infoDesc, infoFooter } p errors =
+  List.intercalate "\n\n" $ catMaybes
     [ infoHeader
     , fmap (List.intercalate "\n" . splitWords 50) infoDesc
-    , Just "Available environment variables:"
-    , Just (List.intercalate "\n" (helpParserDoc p))
+    , Just (helpDoc p)
     , fmap (List.intercalate "\n" . splitWords 50) infoFooter
-    ] ++ map Just (helpFailuresDoc fs)
+    ] ++ helpErrors errors
 
+-- | A pretty-printed list of recognized environment variables suitable for usage messages.
+helpDoc :: Parser a -> String
+helpDoc p =
+  List.intercalate "\n" ("Available environment variables:\n" : helpParserDoc p)
+
 helpParserDoc :: Parser a -> [String]
 helpParserDoc = concat . Map.elems . foldAlt (\v -> Map.singleton (varfName v) (helpVarfDoc v)) . unParser
 
@@ -39,13 +43,16 @@
      where k = length varfName
            t = maybe h (\s -> h ++ " (default: " ++ s ++")") varfHelpDef
 
-helpFailuresDoc :: [Error] -> [String]
-helpFailuresDoc [] = []
-helpFailuresDoc fs = ["Parsing errors:", List.intercalate "\n" (map helpFailureDoc (List.sortBy (comparing varName) fs))]
+helpErrors :: [Error] -> [String]
+helpErrors [] = []
+helpErrors fs =
+  [ "Parsing errors:"
+  , List.intercalate "\n" (map helpError (List.sortBy (comparing varName) fs))
+  ]
 
-helpFailureDoc :: Error -> String
-helpFailureDoc (ParseError n e)  = "  " ++ n ++ " cannot be parsed: " ++ e
-helpFailureDoc (ENoExistError n) = "  " ++ n ++ " is unset"
+helpError :: Error -> String
+helpError (ParseError n e)  = "  " ++ n ++ " cannot be parsed: " ++ e
+helpError (ENoExistError n) = "  " ++ n ++ " is unset"
 
 varName :: Error -> String
 varName (ParseError n _)  = n
@@ -66,4 +73,4 @@
   prep acc = [unwords (reverse acc)]
 
 indent :: Int -> String -> String
-indent n s = replicate n ' ' <> s
+indent n s = replicate n ' ' ++ s
diff --git a/src/Env/Parse.hs b/src/Env/Parse.hs
--- a/src/Env/Parse.hs
+++ b/src/Env/Parse.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveFunctor #-}
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE ViewPatterns #-}
@@ -32,7 +33,9 @@
 import           Control.Applicative
 import           Data.Map (Map)
 import qualified Data.Map as Map
+#if __GLASGOW_HASKELL__ < 710
 import           Data.Monoid (Monoid(..))
+#endif
 import           Data.String (IsString(..))
 
 import           Env.Free
diff --git a/src/Env/Val.hs b/src/Env/Val.hs
--- a/src/Env/Val.hs
+++ b/src/Env/Val.hs
@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE DeriveFunctor #-}
 module Env.Val
   ( Val(..)
@@ -6,10 +7,13 @@
   ) where
 
 import Control.Applicative
-import Data.Monoid (Monoid(..), (<>))
+#if __GLASGOW_HASKELL__ < 710
+import Data.Monoid (Monoid(..))
+#endif
+import Data.Monoid ((<>))
 
 
--- | An isomorphic to 'Either' type with the accumulating 'Applicative' instance
+-- | A type isomorphic to 'Either' with the accumulating 'Applicative' instance.
 data Val e a
   = Err e
   | Ok  a