diff --git a/src/Data/String/Transform.hs b/src/Data/String/Transform.hs
--- a/src/Data/String/Transform.hs
+++ b/src/Data/String/Transform.hs
@@ -1,8 +1,5 @@
-{-# LANGUAGE FlexibleInstances    #-}
-{-# LANGUAGE IncoherentInstances  #-}
-{-# LANGUAGE Safe                 #-}
-{-# LANGUAGE TypeSynonymInstances #-}
-{-# LANGUAGE UndecidableInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE Safe              #-}
 module Data.String.Transform where
 
 import qualified Data.ByteString           as B
@@ -32,9 +29,6 @@
 instance ToString TL.Text where
     toString = TL.unpack
 
-instance Show a => ToString a where
-    toString = show
-
 class ToByteStringStrict a where
     toByteStringStrict :: a -> B.ByteString
 
@@ -53,9 +47,6 @@
 instance ToByteStringStrict TL.Text where
     toByteStringStrict = T.encodeUtf8 . TL.toStrict
 
-instance Show a => ToByteStringStrict a where
-    toByteStringStrict = toByteStringStrict . show
-
 class ToByteStringLazy a where
     toByteStringLazy :: a -> BL.ByteString
 
@@ -74,9 +65,6 @@
 instance ToByteStringLazy TL.Text where
     toByteStringLazy = TL.encodeUtf8
 
-instance Show a => ToByteStringLazy a where
-    toByteStringLazy = toByteStringLazy . show
-
 class ToTextStrict a where
     toTextStrict :: a -> T.Text
 
@@ -95,9 +83,6 @@
 instance ToTextStrict TL.Text where
     toTextStrict = TL.toStrict
 
-instance Show a => ToTextStrict a where
-    toTextStrict = toTextStrict . show
-
 class ToTextLazy a where
     toTextLazy :: a -> TL.Text
 
@@ -115,6 +100,3 @@
 
 instance ToTextLazy TL.Text where
     toTextLazy = id
-
-instance Show a => ToTextLazy a where
-    toTextLazy = toTextLazy . show
diff --git a/string-transform.cabal b/string-transform.cabal
--- a/string-transform.cabal
+++ b/string-transform.cabal
@@ -1,9 +1,11 @@
--- This file has been generated from package.yaml by hpack version 0.17.1.
+-- This file has been generated from package.yaml by hpack version 0.20.0.
 --
 -- see: https://github.com/sol/hpack
+--
+-- hash: 29bfa4a42fbd19c8676a3a49f89a49041935aec7c3adff0fcb0197bf80d1179a
 
 name:           string-transform
-version:        0.1.0
+version:        0.1.1
 synopsis:       simple and easy haskell string transform wrapper
 category:       Text
 homepage:       https://github.com/ncaq/string-transform#readme
@@ -28,12 +30,14 @@
       src
   ghc-options: -Wall
   build-depends:
-      base >= 4.7 && < 5
+      base >=4.7 && <5
     , bytestring
     , text
     , utf8-string
   exposed-modules:
       Data.String.Transform
+  other-modules:
+      Paths_string_transform
   default-language: Haskell2010
 
 test-suite tasty
@@ -43,12 +47,14 @@
       test
   ghc-options: -Wall
   build-depends:
-      base >= 4.7 && < 5
+      base >=4.7 && <5
     , bytestring
-    , text
-    , utf8-string
     , string-transform
     , tasty
     , tasty-hunit
     , tasty-smallcheck
+    , text
+    , utf8-string
+  other-modules:
+      Paths_string_transform
   default-language: Haskell2010
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -2,6 +2,7 @@
 module Main (main) where
 
 import           Data.String.Transform
+import qualified Data.Text             as T
 import           Test.Tasty
 import           Test.Tasty.HUnit
 import           Test.Tasty.SmallCheck
@@ -34,8 +35,6 @@
 
 hunitTest :: [TestTree]
 hunitTest =
-    [ testCase "toString 1" (toString 1 @?= "1")
-    , testCase "toByteStringStrict 1" (toByteStringStrict 1 @?= toByteStringStrict "1")
-    , testCase "toTextStrict 1" (toTextStrict 1 @?= toTextStrict "1")
-    , testCase "toByteStringStrict 日本語" (toString (toByteStringStrict "日本語") @?= "日本語")
+    [ testCase "toByteStringStrict 日本語" (toString (toByteStringStrict "日本語") @?= "日本語")
+    , testCase "toString Text" (toString (T.pack "foo") @?= "foo")
     ]