diff --git a/Data/IP/Builder.hs b/Data/IP/Builder.hs
--- a/Data/IP/Builder.hs
+++ b/Data/IP/Builder.hs
@@ -1,6 +1,8 @@
 {-# LANGUAGE BangPatterns #-}
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE MagicHash #-}
+{-# LANGUAGE StrictData #-}
+{-# LANGUAGE NoStrict #-}
 {-# LANGUAGE TupleSections #-}
 
 module Data.IP.Builder
@@ -43,7 +45,6 @@
 toB = P.liftFixedToBounded
 {-# INLINE toB #-}
 
-{-# INLINE ipv4Bounded #-}
 ipv4Bounded :: P.BoundedPrim Word32
 ipv4Bounded =
     quads >$< ((P.word8Dec >*< dotsep) >*< (P.word8Dec >*< dotsep))
@@ -57,24 +58,23 @@
     {-# INLINE qfin #-}
     dotsep = const 0x2e >$< toB P.word8
 
--- | For each of the 32-bit chunks of an IPv6 address, encode how it should be
--- displayed in the presentation form of the address, based its location
--- relative to the "best gap", i.e.  the left-most longest run of zeros. The
--- "hi" and, or "lo" parts are accompanied by occasional units mapped to colons.
+-- | For each 32-bit chunk of an IPv6 address, encode its display format in the
+-- presentation form of the address, based on its location relative to the
+-- "best gap", i.e. the left-most longest run of zeros. The "hi" (H) and/or
+-- "lo" (L) 16 bits may be accompanied by colons (C) on the left and/or right.
 --
-data FF = CHL {-# UNPACK #-} ! Word32  -- ^ :<h>:<l>
-        | HL  {-# UNPACK #-} ! Word32  -- ^  <h>:<l>
-        | NOP                          -- ^  nop
-        | COL                          -- ^ :
-        | CLO {-# UNPACK #-} ! Word32  -- ^     :<l>
-        | CC                           -- ^ :   :
-        | CHC {-# UNPACK #-} ! Word32  -- ^ :<h>:
-        | HC  {-# UNPACK #-} ! Word32  -- ^  <h>:
+data FF = CHL Word32  -- ^ :<h>:<l>
+        | HL  Word32  -- ^  <h>:<l>
+        | NOP         -- ^  nop
+        | COL         -- ^ :
+        | CC          -- ^ :   :
+        | CLO Word32  -- ^     :<l>
+        | CHC Word32  -- ^ :<h>:
+        | HC  Word32  -- ^  <h>:
 
 -- Build an IPv6 address in conformance with
 -- [RFC5952](http://tools.ietf.org/html/rfc5952 RFC 5952).
 --
-{-# INLINE ipv6Bounded #-}
 ipv6Bounded :: P.BoundedPrim (Word32, Word32, Word32, Word32)
 ipv6Bounded =
     P.condB generalCase
@@ -113,33 +113,16 @@
     --
     output32 :: P.BoundedPrim FF
     output32 =
-        P.condB ffCond03
-          ( P.condB ffCond01
-               ( P.condB ffCond0
-                   build_CHL        -- :<h>:<l>
-                   build_HL )       -- <h>:<l>
-               ( P.condB ffCond2
-                   build_NOP        -- nop
-                   build_COL ) )    -- :
-          ( P.condB ffCond45
-               ( P.condB ffCond4
-                   build_CLO        -- :<l>
-                   build_CC  )      -- :   :
-               ( P.condB ffCond6
-                   build_CHC        -- :<h>:
-                   build_HC ) )     -- <h>:
-
-    -- Branch selection predicates
-    ffCond03 = \case { CHL _ -> True; HL  _ -> True;
-                       NOP   -> True; COL   -> True; _ -> False }
-    ffCond01 = \case { CHL _ -> True; HL  _ -> True; _ -> False }
-    ffCond45 = \case { CC    -> True; CLO _ -> True; _ -> False }
-    ffCond0  = \case { CHL _ -> True;                _ -> False }
-    ffCond2  = \case { NOP   -> True;                _ -> False }
-    ffCond4  = \case { CLO _ -> True;                _ -> False }
-    ffCond6  = \case { CHC _ -> True;                _ -> False }
+        P.condB (\case { CHL _ -> True; _ -> False }) build_CHL $ -- :hi:lo
+        P.condB (\case { HL _  -> True; _ -> False }) build_HL  $ --  hi:lo
+        P.condB (\case { NOP   -> True; _ -> False }) build_NOP $ --
+        P.condB (\case { COL   -> True; _ -> False }) build_COL $ -- :
+        P.condB (\case { CC    -> True; _ -> False }) build_CC  $ -- :  :
+        P.condB (\case { CLO _ -> True; _ -> False }) build_CLO $ --    :lo
+        P.condB (\case { CHC _ -> True; _ -> False }) build_CHC $ -- :hi:
+                                                      build_HC    --  hi:
 
-    -- encoders for the seven field format (FF) cases.
+    -- encoders for the eight field format (FF) cases.
     --
     build_CHL = (\ (CHL w) -> ( fstUnit (hi16 w), fstUnit (lo16 w) ) )
                 >$< (colsep >*< P.word16Hex)
diff --git a/iproute.cabal b/iproute.cabal
--- a/iproute.cabal
+++ b/iproute.cabal
@@ -1,5 +1,5 @@
 Name:                   iproute
-Version:                1.7.9
+Version:                1.7.10
 Author:                 Kazu Yamamoto <kazu@iij.ad.jp>
 Maintainer:             Kazu Yamamoto <kazu@iij.ad.jp>
 License:                BSD3