diff --git a/Codec/Encryption/OpenPGP/Types/Internal/Base.hs b/Codec/Encryption/OpenPGP/Types/Internal/Base.hs
--- a/Codec/Encryption/OpenPGP/Types/Internal/Base.hs
+++ b/Codec/Encryption/OpenPGP/Types/Internal/Base.hs
@@ -29,9 +29,9 @@
 import qualified Data.Aeson.TH as ATH
 import Data.Byteable (Byteable)
 import Data.ByteArray (ByteArrayAccess)
-import Data.ByteString.Builder (lazyByteStringHex, toLazyByteString)
 import Data.ByteString.Lazy (ByteString)
 import qualified Data.ByteString as B
+import qualified Data.ByteString.Base16.Lazy as B16L
 import qualified Data.ByteString.Lazy as BL
 import qualified Data.ByteString.Lazy.Char8 as BLC8
 import Data.Char (toLower, toUpper)
@@ -330,7 +330,7 @@
     pretty = hsep . punctuate space . map hsep . chunksOf 5 . map text . chunksOf 4 . take 40 . bsToHexUpper . unTOF . unpack
 
 bsToHexUpper :: ByteString -> String
-bsToHexUpper = map toUpper . BLC8.unpack . toLazyByteString . lazyByteStringHex
+bsToHexUpper = map toUpper . BLC8.unpack . B16L.encode
 
 hexToW8s :: ReadS Word8
 hexToW8s = concatMap readHex . chunksOf 2 . map toLower
diff --git a/hOpenPGP.cabal b/hOpenPGP.cabal
--- a/hOpenPGP.cabal
+++ b/hOpenPGP.cabal
@@ -1,5 +1,5 @@
 Name:                hOpenPGP
-Version:             2.5.3
+Version:             2.5.4
 Synopsis:            native Haskell implementation of OpenPGP (RFC4880)
 Description:         native Haskell implementation of OpenPGP (RFC4880), plus Camellia (RFC5581)
 Homepage:            http://floss.scru.org/hOpenPGP/
@@ -188,10 +188,11 @@
   Build-depends: aeson
                , attoparsec
                , base                  > 4       && < 5
+               , base16-bytestring
                , base64-bytestring
                , bifunctors
                , byteable
-               , bytestring            >= 0.10.0.0
+               , bytestring
                , bzlib
                , binary                >= 0.6.4.0
                , binary-conduit
@@ -238,9 +239,10 @@
                , aeson
                , attoparsec
                , base                  > 4       && < 5
+               , base16-bytestring
                , bifunctors
                , byteable
-               , bytestring            >= 0.10.0.0
+               , bytestring
                , bzlib
                , binary                >= 0.6.4.0
                , binary-conduit
@@ -288,10 +290,11 @@
   Build-depends: hOpenPGP
                , aeson
                , base                  > 4       && < 5
+               , base16-bytestring
                , base64-bytestring
                , bifunctors
                , byteable
-               , bytestring            >= 0.10.0.0
+               , bytestring
                , bzlib
                , binary                >= 0.6.4.0
                , binary-conduit
@@ -336,4 +339,4 @@
 source-repository this
   type:     git
   location: git://git.debian.org/users/clint/hOpenPGP.git
-  tag:      v2.5.3
+  tag:      v2.5.4