diff --git a/crypto-conduit.cabal b/crypto-conduit.cabal
--- a/crypto-conduit.cabal
+++ b/crypto-conduit.cabal
@@ -1,6 +1,6 @@
 Cabal-version:       >= 1.8
 Name:                crypto-conduit
-Version:             0.1.2
+Version:             0.1.3.1
 Synopsis:            Conduit interface for cryptographic operations (from crypto-api).
 Homepage:            https://github.com/meteficha/crypto-conduit
 License:             BSD3
@@ -23,6 +23,10 @@
   Type:     git
   Location: git://github.com/meteficha/crypto-conduit.git
 
+Flag old-crypto-api
+  Description: Use crypto-api < 0.9.
+  Default: False
+
 Library
   Hs-Source-Dirs: src
   Exposed-modules:
@@ -31,20 +35,24 @@
     base         >= 3   && < 5,
     bytestring   >= 0.9 && < 0.10,
     cereal       >= 0.3 && < 0.4,
-    crypto-api   >= 0.8 && < 0.9,
     conduit      >= 0.2 && < 0.3,
     transformers == 0.2.*
+  if flag(old-crypto-api)
+    Build-depends: crypto-api >= 0.8 && < 0.9
+    CPP-options:   -DOLD_CRYPTO_API
+  else
+    Build-depends: crypto-api >= 0.9 && < 0.10
   GHC-options: -Wall
 
 Test-suite runtests
   Type: exitcode-stdio-1.0
   Build-depends:
-    base         >= 3   && < 5,
-    bytestring   >= 0.9 && < 0.10,
-    cereal       >= 0.3 && < 0.4,
-    crypto-api   >= 0.8 && < 0.9,
-    conduit      >= 0.2 && < 0.3,
-    transformers == 0.2.*,
+    base,
+    bytestring,
+    cereal,
+    crypto-api   >= 0.9,
+    conduit,
+    transformers,
 
     cryptocipher == 0.3.*,
     cryptohash   == 0.7.*,
diff --git a/src/Crypto/Conduit.hs b/src/Crypto/Conduit.hs
--- a/src/Crypto/Conduit.hs
+++ b/src/Crypto/Conduit.hs
@@ -1,4 +1,4 @@
-{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE BangPatterns, CPP #-}
 -- | This module contains wrappers for cryptographic functions
 -- using the @conduit@ package.  Currently there is support for
 -- hashes, HMACs and many modes of block ciphers (but not
@@ -110,7 +110,13 @@
 
 -- | A 'Sink' that computes the HMAC of a stream of
 -- 'B.ByteString'@s@ and creates a digest @d@.
-sinkHmac :: (Resource m, C.Hash ctx d) => C.MacKey -> Sink B.ByteString m d
+sinkHmac :: (Resource m, C.Hash ctx d) =>
+#if OLD_CRYPTO_API
+            C.MacKey
+#else
+            C.MacKey ctx d
+#endif
+         -> Sink B.ByteString m d
 sinkHmac (C.MacKey key) = blocked AnyMultiple blockSize =$ sink
     where
       --------- Taken and modified from Crypto.HMAC:
diff --git a/tests/runtests.hs b/tests/runtests.hs
--- a/tests/runtests.hs
+++ b/tests/runtests.hs
@@ -103,7 +103,7 @@
     in d1 == d2
 
 
-prop_sinkHmac :: C.Hash ctx d => d -> C.MacKey -> L.ByteString -> Bool
+prop_sinkHmac :: C.Hash ctx d => d -> C.MacKey ctx d -> L.ByteString -> Bool
 prop_sinkHmac d mackey input =
     let d1 = runPureResource $ sourceList (L.toChunks input) $$ sinkHmac mackey
         d2 = C.hmac mackey input `asTypeOf` d