diff --git a/ipython-kernel.cabal b/ipython-kernel.cabal
--- a/ipython-kernel.cabal
+++ b/ipython-kernel.cabal
@@ -1,5 +1,5 @@
 name:                ipython-kernel
-version:             0.12.0.0
+version:             0.12.1.0
 synopsis:            A library for creating kernels for IPython frontends
 
 description:         ipython-kernel is a library for communicating with frontends for the interactive IPython framework. It is used extensively in IHaskell, the interactive Haskell environment.
@@ -36,21 +36,21 @@
   hs-source-dirs:      src
   default-language:    Haskell2010
   build-depends:       base                 >=4.9 && <5,
-                       aeson           ,
-                       binary          ,
-                       bytestring      ,
-                       containers      ,
-                       cryptonite      ,
-                       directory       ,
-                       temporary       ,
-                       filepath        ,
-                       process         ,
-                       memory          ,
-                       text            ,
-                       transformers    ,
+                       aeson               ,
+                       base16-bytestring   ,
+                       binary              ,
+                       bytestring          ,
+                       containers          ,
+                       cryptohash-sha256   ,
+                       directory           ,
+                       temporary           ,
+                       filepath            ,
+                       process             ,
+                       text                ,
+                       transformers        ,
                        unordered-containers,
-                       uuid            ,
-                       zeromq4-haskell ,
+                       uuid                ,
+                       zeromq4-haskell     ,
                        parsec
 
 -- Example program
diff --git a/src/IHaskell/IPython/ZeroMQ.hs b/src/IHaskell/IPython/ZeroMQ.hs
--- a/src/IHaskell/IPython/ZeroMQ.hs
+++ b/src/IHaskell/IPython/ZeroMQ.hs
@@ -17,11 +17,9 @@
 import           Control.Concurrent
 import           Control.Exception
 import           Control.Monad
-import qualified Crypto.Hash as Hash
-import           Crypto.Hash.Algorithms (SHA256)
-import qualified Crypto.MAC.HMAC as HMAC
+import qualified Crypto.Hash.SHA256 as Hash
 import           Data.Aeson
-import qualified Data.ByteArray.Encoding as Encoding
+import qualified Data.ByteString.Base16 as B16
 import           Data.ByteString (ByteString)
 import qualified Data.ByteString.Char8 as Char
 import qualified Data.ByteString.Lazy as LBS
@@ -342,9 +340,7 @@
 
     -- Compute the HMAC SHA-256 signature of a bytestring message.
     hmac :: ByteString -> ByteString
-    hmac = (Encoding.convertToBase Encoding.Base16 :: Hash.Digest SHA256 -> ByteString)
-      . HMAC.hmacGetDigest
-      . HMAC.hmac hmackey
+    hmac = B16.encode . Hash.hmac hmackey
 
     -- Pieces of the message.
     hdr = header msg