diff --git a/Data/Text/Format/Heavy/Instances.hs b/Data/Text/Format/Heavy/Instances.hs
--- a/Data/Text/Format/Heavy/Instances.hs
+++ b/Data/Text/Format/Heavy/Instances.hs
@@ -12,7 +12,11 @@
 import Data.Default
 import qualified Data.Map as M
 import qualified Data.Text as T
+import qualified Data.Text.Encoding as TE
 import qualified Data.Text.Lazy as TL
+import qualified Data.Text.Lazy.Encoding as TLE
+import qualified Data.ByteString as BS
+import qualified Data.ByteString.Lazy as BSL
 import qualified Data.Text.Lazy.Builder as B
 import Data.Text.Lazy.Builder.Int (decimal, hexadecimal)
 
@@ -88,6 +92,20 @@
     case parseGenericFormat fmtStr of
       Left err -> Left $ show err
       Right fmt -> Right $ formatStr fmt text
+
+instance Formatable BS.ByteString where
+  formatVar Nothing text = Right $ formatStr def $ TL.fromStrict $ TE.decodeUtf8 text
+  formatVar (Just fmtStr) text =
+    case parseGenericFormat fmtStr of
+      Left err -> Left $ show err
+      Right fmt -> Right $ formatStr fmt $ TL.fromStrict $ TE.decodeUtf8 text
+
+instance Formatable BSL.ByteString where
+  formatVar Nothing text = Right $ formatStr def $ TLE.decodeUtf8 text
+  formatVar (Just fmtStr) text =
+    case parseGenericFormat fmtStr of
+      Left err -> Left $ show err
+      Right fmt -> Right $ formatStr fmt $ TLE.decodeUtf8 text
 
 instance Formatable Bool where
   formatVar Nothing x = Right $ formatBool def x
diff --git a/text-format-heavy.cabal b/text-format-heavy.cabal
--- a/text-format-heavy.cabal
+++ b/text-format-heavy.cabal
@@ -1,5 +1,5 @@
 name:                text-format-heavy
-version:             0.1.1.0
+version:             0.1.2.0
 synopsis:            Full-weight string formatting library, analog of Python's string.format
 description:         This package contains full-featured string formatting function, similar to
                      Python's string.format. Features include:
@@ -46,6 +46,7 @@
   other-extensions:    ExistentialQuantification
   build-depends:       base >=4.8 && <5,
                        text >=1.2 && <1.3,
+                       bytestring >= 0.10,
                        parsec >=3.1 && <3.2,
                        containers >= 0.5,
                        data-default >= 0.7,