diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2015 philopon
+Copyright (c) 2015 Hirotomo Moriwaki
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the
diff --git a/bytestring-read.cabal b/bytestring-read.cabal
--- a/bytestring-read.cabal
+++ b/bytestring-read.cabal
@@ -1,5 +1,5 @@
 name:                bytestring-read
-version:             0.2.0
+version:             0.2.1
 synopsis:            fast ByteString to number converting library
 description:         benchmark: <http://philopon.github.io/bytestring-read/bench.html>
 license:             MIT
@@ -19,7 +19,7 @@
                        Data.ByteString.Read.Fractional
                        Data.ByteString.Read.Integral
                        Data.ByteString.Read.DEPRECATED
-  build-depends:       base         >=4.6  && <4.8
+  build-depends:       base         >=4.6  && <4.9
                      , bytestring   >=0.10 && <0.11
                      , types-compat >=0.1  && <0.2
   hs-source-dirs:      src
@@ -31,7 +31,7 @@
   main-is:             bench/main.hs
   build-depends:       base
                      , bytestring-read
-                     , bytestring        >=0.10 && <0.11
+                     , bytestring
                      , text
                      , bytestring-lexing >=0.4  && <0.5
                      , criterion         >=1.0  && <1.1
@@ -45,7 +45,7 @@
   main-is:             tests/tasty.hs
   build-depends:       base
                      , bytestring-read
-                     , bytestring        >=0.10 && <0.11
+                     , bytestring
                      , tasty             >=0.10 && <0.11
                      , tasty-quickcheck  >=0.8  && <0.9
   ghc-options:         -Wall -O2
@@ -55,6 +55,6 @@
   type:                exitcode-stdio-1.0
   ghc-options:         -threaded
   main-is:             tests/doctest.hs
-  build-depends:       base    >=4.6 && <4.8
+  build-depends:       base
                      , doctest >=0.9 && <0.10
   default-language:    Haskell2010
diff --git a/src/Data/ByteString/Read.hs b/src/Data/ByteString/Read.hs
--- a/src/Data/ByteString/Read.hs
+++ b/src/Data/ByteString/Read.hs
@@ -15,7 +15,6 @@
     , module Data.ByteString.Read.DEPRECATED
     ) where
 
-import Control.Applicative
 import Control.Arrow
 
 import Data.ByteString(ByteString)
@@ -45,7 +44,7 @@
 signed :: Num r => (ByteString -> Maybe (r, ByteString)) -> ByteString -> Maybe (r, ByteString)
 signed f s
     | S.null s = Nothing
-    | unsafeHead s == minus = first negate <$> f (unsafeTail s)
+    | unsafeHead s == minus = first negate `fmap` f (unsafeTail s)
     | unsafeHead s == plus  = f (unsafeTail s)
     | otherwise = f s
   where