diff --git a/Network/Wai/Middleware/Static.hs b/Network/Wai/Middleware/Static.hs
--- a/Network/Wai/Middleware/Static.hs
+++ b/Network/Wai/Middleware/Static.hs
@@ -19,13 +19,14 @@
     ) where
 
 import Control.Monad.Trans (liftIO)
+import qualified Data.ByteString as B
 import Data.List
 import qualified Data.Map as M
 import Data.Maybe (fromMaybe)
 import Data.Monoid
 import qualified Data.Text as T
 
-import Network.HTTP.Types (status200, Ascii)
+import Network.HTTP.Types (status200)
 import System.Directory (doesFileExist)
 import qualified System.FilePath as FP
 
@@ -124,6 +125,8 @@
                                                    Nothing
                         else app req)
           (tryPolicy p $ T.unpack $ T.intercalate "/" $ pathInfo req)
+
+type Ascii = B.ByteString
 
 getMimeType :: FilePath -> Ascii
 getMimeType = go . extensions
diff --git a/wai-middleware-static.cabal b/wai-middleware-static.cabal
--- a/wai-middleware-static.cabal
+++ b/wai-middleware-static.cabal
@@ -1,5 +1,5 @@
 Name:                wai-middleware-static
-Version:             0.3.0
+Version:             0.3.1
 Synopsis:            WAI middleware that intercepts requests to static files.
 Homepage:            https://github.com/xich/scotty
 Bug-reports:         https://github.com/xich/scotty/issues
@@ -22,9 +22,10 @@
   Exposed-modules:     Network.Wai.Middleware.Static
   default-language:    Haskell2010
   Build-depends:       base             >= 4.3.1 && < 5,
+                       bytestring       >= 0.9.2.1,
                        containers       >= 0.4,
                        directory        >= 1.1,
-                       http-types       >= 0.6.8 && < 0.7,
+                       http-types       >= 0.6.8 && < 0.8,
                        mtl              >= 2.0.1,
                        filepath         >= 1.3.0.0,
                        text             >= 0.11.1,