diff --git a/protolude.cabal b/protolude.cabal
index f2125c6b0..eb55ad86d 100644
--- a/protolude.cabal
+++ b/protolude.cabal
@@ -43,6 +43,7 @@ library
     List
     Monad
     Show
+    Conv
     Either
     Functor
     Semiring
diff --git a/src/Conv.hs b/src/Conv.hs
new file mode 100644
index 000000000..2b092b56f
--- /dev/null
+++ b/src/Conv.hs
@@ -0,0 +1,75 @@
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+
+
+module Conv (
+  StringConv (..)
+, toS
+, toSL
+, Leniency (..)
+) where
+
+import Data.ByteString.Char8      as B
+import Data.ByteString.Lazy.Char8 as LB
+import Data.Text                  as T
+import Data.Text.Encoding         as T
+import Data.Text.Encoding.Error   as T
+import Data.Text.Lazy             as LT
+import Data.Text.Lazy.Encoding    as LT
+
+import Base
+import Data.Eq (Eq(..))
+import Data.Ord (Ord(..))
+import Data.Function ((.), id)
+import Data.String (String)
+import Control.Applicative (pure)
+
+data Leniency = Lenient | Strict
+  deriving (Eq,Show,Ord,Enum,Bounded)
+
+class StringConv a b where
+  strConv :: Leniency -> a -> b
+
+toS :: StringConv a b => a -> b
+toS = strConv Strict
+
+toSL :: StringConv a b => a -> b
+toSL = strConv Lenient
+
+instance StringConv String String where strConv _ = id
+instance StringConv String B.ByteString where strConv _ = B.pack
+instance StringConv String LB.ByteString where strConv _ = LB.pack
+instance StringConv String T.Text where strConv _ = T.pack
+instance StringConv String LT.Text where strConv _ = LT.pack
+
+instance StringConv B.ByteString String where strConv _ = B.unpack
+instance StringConv B.ByteString B.ByteString where strConv _ = id
+instance StringConv B.ByteString LB.ByteString where strConv _ = LB.fromChunks . pure
+instance StringConv B.ByteString T.Text where strConv = decodeUtf8T
+instance StringConv B.ByteString LT.Text where strConv l = strConv l . LB.fromChunks . pure
+
+instance StringConv LB.ByteString String where strConv _ = LB.unpack
+instance StringConv LB.ByteString B.ByteString where strConv _ = B.concat . LB.toChunks
+instance StringConv LB.ByteString LB.ByteString where strConv _ = id
+instance StringConv LB.ByteString T.Text where strConv l = decodeUtf8T l . strConv l
+instance StringConv LB.ByteString LT.Text where strConv = decodeUtf8LT
+
+instance StringConv T.Text String where strConv _ = T.unpack
+instance StringConv T.Text B.ByteString where strConv _ = T.encodeUtf8
+instance StringConv T.Text LB.ByteString where strConv l = strConv l . T.encodeUtf8
+instance StringConv T.Text LT.Text where strConv _ = LT.fromStrict
+instance StringConv T.Text T.Text where strConv _ = id
+
+instance StringConv LT.Text String where strConv _ = LT.unpack
+instance StringConv LT.Text T.Text where strConv _ = LT.toStrict
+instance StringConv LT.Text LT.Text where strConv _ = id
+instance StringConv LT.Text LB.ByteString where strConv _ = LT.encodeUtf8
+instance StringConv LT.Text B.ByteString where strConv l = strConv l . LT.encodeUtf8
+
+decodeUtf8T :: Leniency -> B.ByteString -> T.Text
+decodeUtf8T Lenient = T.decodeUtf8With T.lenientDecode
+decodeUtf8T Strict = T.decodeUtf8With T.strictDecode
+
+decodeUtf8LT :: Leniency -> LB.ByteString -> LT.Text
+decodeUtf8LT Lenient = LT.decodeUtf8With T.lenientDecode
+decodeUtf8LT Strict = LT.decodeUtf8With T.strictDecode
diff --git a/src/Protolude.hs b/src/Protolude.hs
index 2737e6633..8a03b27f8 100644
--- a/src/Protolude.hs
+++ b/src/Protolude.hs
@@ -27,6 +27,7 @@ import Monad as X
 import Functor as X
 import Either as X
 import Applicative as X
+import Conv as X
 
 import Base as Base hiding (
     putStr
@@ -279,14 +280,6 @@ import Data.Text.Lazy (
   , fromStrict
   )
 
-import Data.String.Conv as X (
-    strConv
-  , toS
-  , toSL
-  , Leniency(..)
-  , StringConv
-  )
-
 import Data.String as X (IsString)
 
 -- Printf