diff --git a/Yesod/Helpers/Static.hs b/Yesod/Helpers/Static.hs
index acd2a70b..744de2ad 100644
--- a/Yesod/Helpers/Static.hs
+++ b/Yesod/Helpers/Static.hs
@@ -49,8 +49,8 @@ import Web.Routes
 
 import qualified Data.ByteString.Lazy as L
 import Data.Digest.Pure.MD5
-import qualified Codec.Binary.Base64Url
-import qualified Data.ByteString as S
+import qualified Data.ByteString.Base64
+import qualified Data.ByteString.Char8 as S8
 import qualified Data.Serialize
 
 #if TEST
@@ -188,8 +188,13 @@ caseGetFileList = do
 --
 -- This function returns the first 8 characters of the hash.
 base64md5 :: L.ByteString -> String
-base64md5 = take 8
-          . Codec.Binary.Base64Url.encode
-          . S.unpack
+base64md5 = map go
+          . take 8
+          . S8.unpack
+          . Data.ByteString.Base64.encode
           . Data.Serialize.encode
           . md5
+  where
+    go '+' = '-'
+    go '/' = '_'
+    go c   = c
diff --git a/yesod.cabal b/yesod.cabal
index 228f7a02..a731b98d 100644
--- a/yesod.cabal
+++ b/yesod.cabal
@@ -37,7 +37,7 @@ library
                    , pureMD5                   >= 1.1.0.0  && < 2.2
                    , random                    >= 1.0.0.2  && < 1.1
                    , cereal                    >= 0.2      && < 0.4
-                   , dataenc                   >= 0.13.0.2 && < 0.14
+                   , base64-bytestring         >= 0.1      && < 0.2
                    , old-locale                >= 1.0.0.2  && < 1.1
                    , persistent                >= 0.3.0    && < 0.4
                    , neither                   >= 0.1.0    && < 0.2