diff --git a/png-file.cabal b/png-file.cabal
--- a/png-file.cabal
+++ b/png-file.cabal
@@ -2,7 +2,7 @@
 cabal-version:	>= 1.8
 
 name:		png-file
-version:	0.0.1.1
+version:	0.0.1.2
 stability:	Experimental
 author:		Yoshikuni Jujo <PAF01143@nifty.ne.jp>
 maintainer:	Yoshikuni Jujo <PAF01143@nifty.ne.jp>
@@ -24,7 +24,7 @@
 source-repository	this
     type:	git
     location:	git://github.com/YoshikuniJujo/png-file.git
-    tag:	0.0.1.1
+    tag:	0.0.1.2
 
 library
     hs-source-dirs:	src
diff --git a/src/File/Binary/PNG/Chunks.hs b/src/File/Binary/PNG/Chunks.hs
--- a/src/File/Binary/PNG/Chunks.hs
+++ b/src/File/Binary/PNG/Chunks.hs
@@ -27,7 +27,8 @@
 import Language.Haskell.TH (
 	newName, nameBase, litP, stringL,
 	cxt, instanceD, tySynInstD, clause, normalB,
-	conT, appT, conP, varP, wildP, tupP, conE, varE, appE, appsE, infixApp)
+	conT, appT, conP, varP, wildP, tupP, conE, varE, appE, appsE, infixApp,
+	tySynEqn)
 import Language.Haskell.TH.Tools (wrapTypes, makeTypes, nameTypes, mapTypesFun)
 import File.Binary (binary, Field(..), Binary(..))
 import File.Binary.Instances ()
@@ -51,7 +52,8 @@
 			| prefix `isPrefixOf` str = drop (length prefix) str
 			| otherwise = str
 	instanceD (cxt []) (conT ''Field `appT` conT ''Chunk) [
-		tySynInstD ''FieldArgument [conT ''Chunk] [t| (Int, ByteString) |],
+		tySynInstD ''FieldArgument $
+			tySynEqn [conT ''Chunk] [t| (Int, ByteString) |],
 		mapTypesFun 'fromBinary ''Chunk $ \con _ -> do
 			[n, typ] <- mapM newName ["n", "typ"]
 			let (t, c) = if con /= 'ChunkOthers