diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+0.6.3.1
+---
+* Build on GHC 8.4.1
+
 0.6.3
 ---
 * Add `valuePlate`
diff --git a/config-value.cabal b/config-value.cabal
--- a/config-value.cabal
+++ b/config-value.cabal
@@ -1,5 +1,5 @@
 name:                config-value
-version:             0.6.3
+version:             0.6.3.1
 synopsis:            Simple, layout-based value language similar to YAML or JSON
 license:             MIT
 license-file:        LICENSE
@@ -33,7 +33,7 @@
                        Config.Pretty,
                        Config.Value
 
-  build-depends:       base       >= 4.8     && < 4.11,
+  build-depends:       base       >= 4.8     && < 4.12,
                        array      >= 0.4     && < 0.6,
                        pretty     >= 1.1.1.0 && < 1.2,
                        text       >= 1.2.0.4 && < 1.3
diff --git a/config-value.vim b/config-value.vim
--- a/config-value.vim
+++ b/config-value.vim
@@ -10,10 +10,9 @@
 syn match cvDelimiter  "*\|:\|\[\|\]\|,\|{\|}\|="
 
 " Strings and constants -- copied from haskell.vim
-syn match   cvStringGap         contained "\\[\n\ \t]*\\"
-syn match   cvSpecialChar       contained "\\\([0-9]\+\|o[0-7]\+\|x[0-9a-fA-F]\+\|[\"\\'&\\abfnrtv]\|\^[@A-Z^_\[\\\]]\)"
+syn match   cvSpecialChar       contained "\\\([\n\t ]*\\\|[0-9]\+\|o[0-7]\+\|x[0-9a-fA-F]\+\|[\"'&\\abfnrtv]\|\^[@A-Z^_\[\\\]]\)"
 syn match   cvSpecialChar       contained "\\\(NUL\|SOH\|STX\|ETX\|EOT\|ENQ\|ACK\|BEL\|BS\|HT\|LF\|VT\|FF\|CR\|SO\|SI\|DLE\|DC1\|DC2\|DC3\|DC4\|NAK\|SYN\|ETB\|CAN\|EM\|SUB\|ESC\|FS\|GS\|RS\|US\|SP\|DEL\)"
-syn region  cvString            start=+"+  skip=+\\\\\|\\"+  end=+"\|\n+ contains=cvStringGap,cvSpecialChar
+syn region  cvString            start=+"+  skip=+\\\\\|\\"+  end=+"\|\n+ contains=cvSpecialChar
 syn match   cvNumber            "-\=\([0-9]\+\|0[xX][0-9a-fA-F]\+\|0[oO][0-7]\+\|0[bB][0-1]\+\)\>"
 syn match   cvFloat             "-\=[0-9]\+\.[0-9]\+\([eE][-+]\=[0-9]\+\)\=\>"
 syn match   cvFloat             "-\=[0-9]\+[eE][-+]\=[0-9]\+\>"
@@ -27,7 +26,6 @@
 hi def link cvDelimiter                   Delimiter
 
 hi def link cvSpecialChar                 SpecialChar
-hi def link cvStringGap                   SpecialChar
 hi def link cvString                      String
 hi def link cvNumber                      Number
 hi def link cvFloat                       Float
diff --git a/src/Config/Lens.hs b/src/Config/Lens.hs
--- a/src/Config/Lens.hs
+++ b/src/Config/Lens.hs
@@ -1,4 +1,12 @@
--- | Optics for compatibility with the lens package
+{-|
+Module      : Config.Lens
+Description : Lenses and traversals for manipulating 'Value' values.
+Copyright   : (c) Eric Mertens, 2017
+License     : ISC
+Maintainer  : emertens@gmail.com
+
+Lenses and traversals for compatibility with the lens package
+-}
 module Config.Lens
   ( key
   , text
@@ -14,17 +22,17 @@
 import Config.Value
 import Data.Text
 
--- | Apply a function to the subsections of the given value when
--- that value is a @Sections@ and the subsection name matches the
--- given section name 
+-- | Traversal for the subsections of the given 'Value' when
+-- that value is a 'Sections' and the section name matches the
+-- given name.
 key ::
   Applicative f =>
   Text {- ^ section name -} ->
   (Value a -> f (Value a)) -> Value a -> f (Value a)
 key i = sections . traverse . section i
 
--- | Apply a function to the 'Value' contained inside the given
--- 'Value' when it is a section name matches the given name.
+-- | Traversal for the 'Value' contained inside the given
+-- 'Section' when its section name matches the given name.
 section ::
   Applicative f =>
   Text {- ^ section name -} ->
@@ -32,39 +40,37 @@
 section i f s@(Section a j v) | i == j    = Section a j <$> f v
                               | otherwise = pure s
 
--- | Apply a function to the ['Section'] contained inside the given
--- 'Value' when it is a @Sections@.
+-- | Traversal for the ['Section'] contained inside the given
+-- 'Value' when it is a 'Sections'.
 sections :: Applicative f => ([Section a] -> f [Section a]) -> Value a -> f (Value a)
 sections f (Sections a xs) = Sections a <$> f xs
 sections _ v               = pure v
 
--- | Apply a function to the 'Text' contained inside the given
--- 'Value' when it is a @Text@.
+-- | Traversal for the 'Text' contained inside the given 'Value'.
 text :: Applicative f => (Text -> f Text) -> Value a -> f (Value a)
 text f (Text a t) = Text a <$> f t
 text _ v          = pure v
 
--- | Apply a function to the 'Text' contained inside the given
--- 'Value' when it is a @Text@. This traversal is only valid
--- if the output atom is a valid atom!
+-- | Traversal for the 'Atom' contained inside the given 'Value'.
 atom :: Applicative f => (Atom -> f Atom) -> Value a -> f (Value a)
 atom f (Atom a t) = Atom a <$> f t
 atom _ v          = pure v
 
--- | Apply a function to the 'Integer' contained inside the given
--- 'Value' when it is a @Number@.
+-- | Traversal for the 'Integer' contained inside the given
+-- 'Value' when it is a 'Number'.
 number :: Applicative f => (Integer -> f Integer) -> Value a -> f (Value a)
 number f (Number a b n) = Number a b <$> f n
 number _ v              = pure v
 
--- | Apply a function to the ['Value'] contained inside the given
--- 'Value' when it is a @List@.
+-- | Traversal for the ['Value'] contained inside the given
+-- 'Value' when it is a 'List'.
 list :: Applicative f => ([Value a] -> f [Value a]) -> Value a -> f (Value a)
 list f (List a xs) = List a <$> f xs
 list _ v           = pure v
 
--- | Apply a function to any of the immediate values in a list or
--- a sections list. This is intended to be used with Control.Lens.Plated.
+-- | Traversal for the immediate values in a list or a sections list.
+--
+-- This is intended to be used with "Control.Lens.Plated".
 valuePlate :: Applicative f => (Value a -> f (Value a)) -> Value a -> f (Value a)
 valuePlate f (List     a xs) = List     a <$> traverse             f  xs
 valuePlate f (Sections a xs) = Sections a <$> traverse (sectionVal f) xs
@@ -73,14 +79,17 @@
 sectionVal :: Functor f => (Value a -> f (Value a)) -> Section a -> f (Section a)
 sectionVal f (Section a k v) = Section a k <$> f v
 
--- | Apply a function to the 'Value' elements inside the given
--- 'Value' when it is a @List@.
+-- | Traversal for the 'Value' elements inside the given
+-- 'Value' when it is a 'List'.
 --
--- > values = list . traverse
+-- @
+-- 'values' = 'list' . 'traverse'
+-- @
 values :: Applicative f => (Value a -> f (Value a)) -> Value a -> f (Value a)
 values = list . traverse
 
 
+-- | Lens for the annotation component of a 'Value'
 ann :: Functor f => (a -> f a) -> Value a -> f (Value a)
 ann f v =
   case v of
diff --git a/src/Config/LexerUtils.hs b/src/Config/LexerUtils.hs
--- a/src/Config/LexerUtils.hs
+++ b/src/Config/LexerUtils.hs
@@ -3,8 +3,31 @@
 -- to segregate the automatically generated code from the
 -- hand written code. The automatically generated code
 -- causes lots of warnings which mask the interesting warnings.
-module Config.LexerUtils where
+module Config.LexerUtils
+  (
+  -- * Alex wrapper
+    AlexInput
+  , alexGetByte
 
+  -- * Lexer modes
+  , LexerMode(..)
+  , startString
+  , nestMode
+  , endMode
+
+  -- * Token builders
+  , token
+  , token_
+  , section
+  , number
+  , floating
+
+  -- * Final actions
+  , untermString
+  , eofAction
+  , errorAction
+  ) where
+
 import Data.Char            (GeneralCategory(..), generalCategory, digitToInt,
                              isAscii, isSpace, ord, isDigit)
 import Data.Text            (Text)
@@ -30,10 +53,6 @@
        return (b, inp)
 
 ------------------------------------------------------------------------
-
--- | The initial 'Position' for the start of a file
-startPos :: Position
-startPos = Position { posIndex = 0, posLine = 1, posColumn = 1 }
 
 -- | Advance the position according to the kind of character lexed.
 move :: Position -> Char -> Position
diff --git a/src/Config/Pretty.hs b/src/Config/Pretty.hs
--- a/src/Config/Pretty.hs
+++ b/src/Config/Pretty.hs
@@ -1,11 +1,12 @@
 -- | Pretty-printing implementation for 'Value'
-module Config.Pretty where
+module Config.Pretty (pretty) where
 
 import           Data.Char (isPrint, isDigit,intToDigit)
 import           Data.List (mapAccumL)
 import qualified Data.Text as Text
 import           Text.PrettyPrint
 import           Numeric(showIntAtBase)
+import           Prelude hiding ((<>))
 
 import Config.Value
 
diff --git a/src/Config/Tokens.hs b/src/Config/Tokens.hs
--- a/src/Config/Tokens.hs
+++ b/src/Config/Tokens.hs
@@ -4,6 +4,7 @@
   ( Token(..)
   , Located(..)
   , Position(..)
+  , startPos
   , Error(..)
   , layoutPass
   ) where
@@ -15,6 +16,10 @@
   { posIndex, posLine, posColumn :: {-# UNPACK #-} !Int }
   deriving (Read, Show, Ord, Eq)
 
+-- | The initial 'Position' for the start of a file
+startPos :: Position
+startPos = Position { posIndex = 0, posLine = 1, posColumn = 1 }
+
 -- | A value annotated with its text file position
 data Located a = Located
   { locPosition :: {-# UNPACK #-} !Position
@@ -68,10 +73,10 @@
 
 -- | Single step of the layout pass
 step ::
-  Located Token              {- ^ current token          -} ->
-  ([Layout] -> [Located Token]) {- ^ continuation           -} ->
-  [Layout]                      {- ^ stack of layout scopes -} ->
-  [Located Token]            {- ^ token stream with layout -}
+  Located Token                 {- ^ current token            -} ->
+  ([Layout] -> [Located Token]) {- ^ continuation             -} ->
+  [Layout]                      {- ^ stack of layout scopes   -} ->
+  [Located Token]               {- ^ token stream with layout -}
 
 -- start blocks must be indented
 -- tokens before the current layout end the current layout
@@ -85,6 +90,7 @@
     Layout{}:_       | usesLayout t   -> t : next (Layout (toCol t) : cols)
     _                                 -> t : next cols
 
+-- | Extract the column number from a located thing.
 toCol :: Located a -> Int
 toCol = posColumn . locPosition