diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,12 @@
+# Change Log for [sext](https://github.com/dzhus/sext)
+
+### 0.1.3
+
+#### Added
+
+- `ShortByteString` support
+
+#### Fixed
+
+- a bug in `createLeft` which failed to actually pad/truncate strings
+  (reported by Altai-man https://github.com/dzhus/sext/issues/4)
diff --git a/sext.cabal b/sext.cabal
--- a/sext.cabal
+++ b/sext.cabal
@@ -1,5 +1,5 @@
 name: sext
-version: 0.1.2
+version: 0.1.3
 cabal-version: >=1.10
 build-type: Simple
 license: BSD3
@@ -7,11 +7,13 @@
 maintainer: dima@dzhus.org
 homepage: https://github.com/dzhus/sext#readme
 bug-reports: https://github.com/dzhus/sext/issues
-synopsis: Lists, Texts, ByteStrings, and Vectors with type-encoded length
+synopsis: Lists, Texts, ByteStrings and Vectors with type-encoded length
 description:
     Sext (/s/tatic t/ext/) provides type-level safety for basic operations on string-like types (finite lists of elements). Use it when you need static guarantee on lengths of strings produced in your code.
 category: Data, Text, Type System
 author: Dmitry Dzhus
+extra-source-files:
+    CHANGELOG.md
 
 source-repository head
     type: git
@@ -64,7 +66,10 @@
     build-depends:
         base <5,
         template-haskell <2.12,
-        sext <0.2
+        bytestring <0.11,
+        sext <0.2,
+        tasty <0.12,
+        tasty-hunit <0.10
     default-language: Haskell2010
     hs-source-dirs: tests
     ghc-options: -Wall
diff --git a/src/Data/Sext.hs b/src/Data/Sext.hs
--- a/src/Data/Sext.hs
+++ b/src/Data/Sext.hs
@@ -20,13 +20,15 @@
 An example application would be a network exchange protocol built of
 packets with fixed-width fields:
 
-> {-# LANGUAGE DataKinds #-}
-> {-# LANGUAGE OverloadedStrings #-}
-> {-# LANGUAGE TemplateHaskell #-}
->
+@
+{\-\# LANGUAGE DataKinds #-\}
+{\-\# LANGUAGE OverloadedStrings #-\}
+{\-\# LANGUAGE TemplateHaskell #-\}
+@
+
 > import Data.Sext
 >
-> mkPacket :: String -> Sext 32 String
+> mkPacket :: ByteString -> Sext 32 ByteString
 > mkPacket inp =
 >   -- 5-character version signature
 >   $(sext "PKT10") `append`
@@ -35,12 +37,12 @@
 >   -- 2-character payload checksum
 >   checksum
 >   where
->     payload = createLeft ' ' inp
->     checksum :: Sext 2 String
->     checksum = createLeft ' ' $
->                show $ Data.Sext.length payload `mod` 100
+>     payload = createLeft 0x20 inp
+>     checksum :: Sext 2 ByteString
+>     checksum = createLeft 0x20 $
+>                pack $ show $ Data.Sext.length payload `mod` 100
 >
-> message :: Sext 64 String
+> message :: Sext 64 ByteString
 > message = mkPacket "Hello" `append` mkPacket "world"
 
 Sext combinators are defined for members of 'Sextable' class. The
@@ -75,7 +77,7 @@
 
          -- * Sextable class
        , Sext
-       , Sextable(unsafeCreate, unwrap)
+       , Sextable(Elem, unsafeCreate, unwrap)
        )
 
 where
@@ -106,7 +108,7 @@
               Elem a -> a -> Sext i a
 createLeft e s =
   C.unsafeCreate $
-  C.take (C.length s) $
+  C.take t $
   C.append s $
   C.replicate (t - C.length s) e
   where
diff --git a/src/Data/Sext/Class.hs b/src/Data/Sext/Class.hs
--- a/src/Data/Sext/Class.hs
+++ b/src/Data/Sext/Class.hs
@@ -20,6 +20,7 @@
 #ifdef WITH_BS
 import qualified Data.ByteString as B
 import           GHC.Word
+import qualified Data.ByteString.Short as BS
 #endif
 
 #ifdef WITH_TEXT
@@ -131,6 +132,24 @@
   map = B.map
   take = B.take
   drop = B.drop
+
+-- | Sextable instance for 'BS.ShortByteString' uses intermediate
+-- 'B.ByteString's (pinned) for all modification operations.
+instance Sextable BS.ShortByteString where
+  type Elem BS.ShortByteString = Word8
+
+  data Sext i BS.ShortByteString = ByteStringS BS.ShortByteString
+    deriving (Eq, Ord)
+
+  unsafeCreate = ByteStringS
+  unwrap (ByteStringS t) = t
+
+  length = BS.length
+  append a b = BS.toShort $ B.append (BS.fromShort a) (BS.fromShort b)
+  replicate n = BS.toShort . B.replicate n
+  map f = BS.toShort . B.map f . BS.fromShort
+  take n = BS.toShort . B.take n . BS.fromShort
+  drop n = BS.toShort . B.drop n . BS.fromShort
 #endif
 
 
diff --git a/tests/Main.hs b/tests/Main.hs
--- a/tests/Main.hs
+++ b/tests/Main.hs
@@ -2,9 +2,14 @@
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TemplateHaskell #-}
 
+import Data.ByteString.Char8 (ByteString, length, pack)
+import Data.Typeable
+import Test.Tasty
+import Test.Tasty.HUnit
+
 import Data.Sext
 
-mkPacket :: String -> Sext 32 String
+mkPacket :: ByteString -> Sext 32 ByteString
 mkPacket inp =
   -- 5-character version signature
   $(sext "PKT10") `append`
@@ -13,12 +18,19 @@
   -- 2-character payload checksum
   checksum
   where
-    payload = createLeft ' ' inp
-    checksum :: Sext 2 String
-    checksum = createLeft ' ' $
-               show $ Data.Sext.length payload `mod` 100
+    payload = createLeft 0x20 inp
+    checksum :: Sext 2 ByteString
+    checksum = createLeft 0x20 $
+               pack $ show $ Data.Sext.length payload `mod` 100
 
-message :: Sext 64 String
+message :: Sext 64 ByteString
 message = mkPacket "Hello" `append` mkPacket "world"
 
-main = print message
+tests :: [TestTree]
+tests =
+  [ testCase ("The actual length of " ++ show (typeOf message)) $
+    assertEqual "" 64 (Data.ByteString.Char8.length $ unwrap message)
+  ]
+
+main :: IO ()
+main = defaultMain $ testGroup "Tests" tests