diff --git a/bytestring-builder.cabal b/bytestring-builder.cabal
--- a/bytestring-builder.cabal
+++ b/bytestring-builder.cabal
@@ -1,5 +1,5 @@
 name:                bytestring-builder
-version:             0.10.4.1.2
+version:             0.10.6.0.0
 synopsis:            The new bytestring builder, packaged outside of GHC
 description:
   This is the bytestring builder that is debuting in bytestring-0.10.4.0, which
@@ -51,7 +51,7 @@
 source-repository this
   type:     git
   location: http://github.com/lpsmith/bytestring-builder
-  tag:      v0.10.4.1.2
+  tag:      v0.10.6.0.0
 
 Flag bytestring_has_builder
   default: True
diff --git a/src/Data/ByteString/Builder.hs b/src/Data/ByteString/Builder.hs
--- a/src/Data/ByteString/Builder.hs
+++ b/src/Data/ByteString/Builder.hs
@@ -266,7 +266,9 @@
 
 -- HADDOCK only imports
 import qualified Data.ByteString               as S (concat)
-import           Data.Monoid
+#if !(MIN_VERSION_base(4,8,0))
+import           Data.Monoid (Monoid(..))
+#endif
 import           Data.Foldable                      (foldMap)
 import           Data.List                          (intersperse)
 
diff --git a/src/Data/ByteString/Builder/ASCII.hs b/src/Data/ByteString/Builder/ASCII.hs
--- a/src/Data/ByteString/Builder/ASCII.hs
+++ b/src/Data/ByteString/Builder/ASCII.hs
@@ -86,14 +86,19 @@
 
 
 #if defined(__GLASGOW_HASKELL__) && defined(INTEGER_GMP)
+
+#if !(MIN_VERSION_base(4,8,0))
 import           Data.Monoid (mappend)
+# endif
 import           Foreign.C.Types
 
 import qualified Data.ByteString.Builder.Prim.Internal          as P
 import           Data.ByteString.Builder.Prim.Internal.UncheckedShifts
                    ( caseWordSize_32_64 )
 
+# if __GLASGOW_HASKELL__ < 710
 import           GHC.Num     (quotRemInteger)
+# endif
 import           GHC.Types   (Int(..))
 
 
diff --git a/src/Data/ByteString/Builder/Internal.hs b/src/Data/ByteString/Builder/Internal.hs
--- a/src/Data/ByteString/Builder/Internal.hs
+++ b/src/Data/ByteString/Builder/Internal.hs
@@ -129,10 +129,13 @@
 ) where
 
 import           Control.Arrow (second)
-import           Control.Applicative (Applicative(..), (<$>))
--- import           Control.Exception (return)
 
+#if !(MIN_VERSION_base(4,8,0))
 import           Data.Monoid
+import           Control.Applicative (Applicative(..))
+#endif
+import           Control.Applicative ((<$>))
+
 import qualified Data.ByteString               as S
 import qualified Data.ByteString.Internal      as S
 import qualified Data.ByteString.Lazy.Internal as L
@@ -385,7 +388,11 @@
 -- only exported for use in rewriting rules. Use 'mempty' otherwise.
 {-# INLINE[1] empty #-}
 empty :: Builder
-empty = Builder id
+empty = Builder (\cont -> (\range -> cont range))
+-- This eta expansion (hopefully) allows GHC to worker-wrapper the
+-- 'BufferRange' in the 'empty' base case of loops (since
+-- worker-wrapper requires (TODO: verify this) that all paths match
+-- against the wrapped argument.
 
 -- | Concatenate two 'Builder's. This function is only exported for use in rewriting
 -- rules. Use 'mappend' otherwise.
diff --git a/src/Data/ByteString/Builder/Prim/ASCII.hs b/src/Data/ByteString/Builder/Prim/ASCII.hs
--- a/src/Data/ByteString/Builder/Prim/ASCII.hs
+++ b/src/Data/ByteString/Builder/Prim/ASCII.hs
@@ -1,4 +1,8 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE ScopedTypeVariables, ForeignFunctionInterface #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 -- | Copyright   : (c) 2010 Jasper Van der Jeugt
 --                 (c) 2010 - 2011 Simon Meier
 -- License       : BSD3-style (see LICENSE)
diff --git a/src/Data/ByteString/Builder/Prim/Binary.hs b/src/Data/ByteString/Builder/Prim/Binary.hs
--- a/src/Data/ByteString/Builder/Prim/Binary.hs
+++ b/src/Data/ByteString/Builder/Prim/Binary.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE CPP, BangPatterns #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 -- | Copyright   : (c) 2010-2011 Simon Meier
 -- License       : BSD3-style (see LICENSE)
 --
diff --git a/src/Data/ByteString/Builder/Prim/Internal/Base16.hs b/src/Data/ByteString/Builder/Prim/Internal/Base16.hs
--- a/src/Data/ByteString/Builder/Prim/Internal/Base16.hs
+++ b/src/Data/ByteString/Builder/Prim/Internal/Base16.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE CPP #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 -- |
 -- Copyright   : (c) 2011 Simon Meier
 -- License     : BSD3-style (see LICENSE)
diff --git a/src/Data/ByteString/Builder/Prim/Internal/Floating.hs b/src/Data/ByteString/Builder/Prim/Internal/Floating.hs
--- a/src/Data/ByteString/Builder/Prim/Internal/Floating.hs
+++ b/src/Data/ByteString/Builder/Prim/Internal/Floating.hs
@@ -1,4 +1,8 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+#if __GLASGOW_HASKELL__ >= 701
+{-# LANGUAGE Trustworthy #-}
+#endif
 -- |
 -- Copyright   : (c) 2010 Simon Meier
 --
diff --git a/src/Data/ByteString/Builder/Prim/Internal/UncheckedShifts.hs b/src/Data/ByteString/Builder/Prim/Internal/UncheckedShifts.hs
--- a/src/Data/ByteString/Builder/Prim/Internal/UncheckedShifts.hs
+++ b/src/Data/ByteString/Builder/Prim/Internal/UncheckedShifts.hs
@@ -1,4 +1,7 @@
 {-# LANGUAGE CPP, MagicHash #-}
+#if __GLASGOW_HASKELL__ >= 703
+{-# LANGUAGE Unsafe #-}
+#endif
 -- |
 -- Copyright   : (c) 2010 Simon Meier
 --
diff --git a/src/Data/ByteString/Short/Internal.hs b/src/Data/ByteString/Short/Internal.hs
--- a/src/Data/ByteString/Short/Internal.hs
+++ b/src/Data/ByteString/Short/Internal.hs
@@ -108,7 +108,7 @@
 --
 data ShortByteString = SBS ByteArray#
 #if !(MIN_VERSION_base(4,3,0))
-                           Int  -- ^ Prior to ghc-7.0.x, 'ByteArray#'s reported
+           {-# UNPACK #-} !Int  -- ^ Prior to ghc-7.0.x, 'ByteArray#'s reported
                                 -- their length rounded up to the nearest word.
                                 -- This means we have to store the true length
                                 -- separately, wasting a word.
@@ -136,7 +136,8 @@
     mappend = append
     mconcat = concat
 
-instance NFData ShortByteString where rnf !_ = ()
+instance NFData ShortByteString where
+    rnf (SBS {}) = ()
 
 instance Show ShortByteString where
     showsPrec p ps r = showsPrec p (unpackChars ps) r
@@ -364,14 +365,16 @@
     let !len1 = length sbs1
         !len2 = length sbs2
      in len1 == len2
-     && 0 == inlinePerformIO (memcmp_ByteArray (asBA sbs1) (asBA sbs2) len1)
+     && 0 == inlinePerformIO
+               (memcmp_ByteArray (asBA sbs1) (asBA sbs2) len1)
 
 compareBytes :: ShortByteString -> ShortByteString -> Ordering
 compareBytes sbs1 sbs2 =
     let !len1 = length sbs1
         !len2 = length sbs2
         !len  = min len1 len2
-     in case inlinePerformIO (memcmp_ByteArray (asBA sbs1) (asBA sbs2) len) of
+     in case inlinePerformIO
+               (memcmp_ByteArray (asBA sbs1) (asBA sbs2) len) of
           i | i    < 0    -> LT
             | i    > 0    -> GT
             | len2 > len1 -> LT