diff --git a/Crypto/Random/AESCtr.hs b/Crypto/Random/AESCtr.hs
--- a/Crypto/Random/AESCtr.hs
+++ b/Crypto/Random/AESCtr.hs
@@ -22,9 +22,6 @@
 
 import Control.Applicative ((<$>))
 
-#ifdef USE_CRYPTOAPI
-import qualified Crypto.Random as CAPI
-#endif
 import Crypto.Random.API
 
 import System.Random (RandomGen(..))
@@ -60,7 +57,7 @@
     {-# UNPACK #-} !Word128
     {-# UNPACK #-} !Word128
     {-# UNPACK #-} !Word64
-    {-# UNPACK #-} !AES.Key
+    {-# UNPACK #-} !AES.AES
 
 data AESRNG = AESRNG { aesrngState :: RNG
                      , aesrngCache :: ByteString }
@@ -99,10 +96,10 @@
 add64 :: Word128 -> Word128
 add64 (Word128 a b) = if b >= (0xffffffffffffffff-63) then Word128 (a+1) (b+64) else Word128 a (b+64)
 
-makeParams :: ByteString -> (AES.Key, ByteString, ByteString)
+makeParams :: ByteString -> (AES.AES, ByteString, ByteString)
 makeParams b = (key, cnt, iv)
     where
-        key          = AES.initKey $ B.take 32 left2
+        key          = AES.initAES $ B.take 32 left2
         (cnt, left2) = B.splitAt 16 left1
         (iv, left1)  = B.splitAt 16 b
 
@@ -126,7 +123,7 @@
 genNextChunk (RNG iv counter sz key) = (chunk, newrng)
     where
         newrng = RNG (get128 chunk) (add64 counter) (sz+fromIntegral chunkSize) key
-        chunk  = AES.genCTR key (AES.IV bytes) 1024
+        chunk  = AES.genCTR key bytes 1024
         bytes  = put128 (iv `xor128` counter)
 
 getRNGReseedLimit :: RNG -> Int
@@ -166,17 +163,6 @@
 reseedState b rng@(RNG _ cnt1 _ _) = RNG (get128 r16 `xor128` get128 iv2) (cnt1 `xor128` get128 cnt2) 0 key2
     where (r16, _)          = genNextChunk rng
           (key2, cnt2, iv2) = makeParams b
-
-#ifdef USE_CRYPTOAPI
--- going away in 0.4.0. use the CPRG instance.
-instance CAPI.CryptoRandomGen AESRNG where
-    newGen b         = maybe (Left CAPI.NotEnoughEntropy) Right $ make b
-    genSeedLength    = 64
-    genBytes len rng = Right $ genRanBytes rng len
-    reseed b rng
-        | B.length b < 64 = Left CAPI.NotEnoughEntropy
-        | otherwise       = Right $ rng { aesrngState = reseedState b (aesrngState rng) }
-#endif
 
 instance CPRG AESRNG where
     cprgGenBytes len rng          = genRanBytes rng len
diff --git a/cprng-aes.cabal b/cprng-aes.cabal
--- a/cprng-aes.cabal
+++ b/cprng-aes.cabal
@@ -1,5 +1,5 @@
 Name:                cprng-aes
-Version:             0.3.4
+Version:             0.4.0
 Description:         
     Simple crypto pseudo-random-number-generator with really good randomness property.
     .
@@ -34,10 +34,6 @@
   Description:       Use cereal
   Default:           False
 
-Flag cryptoapi
-  Description:       Use cryptoapi
-  Default:           True
-
 Library
   Build-Depends:     base >= 3 && < 5
                    , bytestring
@@ -47,13 +43,10 @@
   Exposed-modules:   Crypto.Random.AESCtr
   ghc-options:       -Wall
 
-  Build-Depends:   cipher-aes >= 0.1 && < 0.2
+  Build-Depends:   cipher-aes >= 0.2 && < 0.3
   if flag(cereal)
     Build-Depends:   cereal >= 0.3.0 && < 0.4.0
     cpp-options:     -DUSE_CEREAL
-  if flag(cryptoapi)
-    Build-Depends:   crypto-api >= 0.8
-    cpp-options:     -DUSE_CRYPTOAPI
 
 Benchmark bench-cprng-aes
   hs-source-dirs:    Benchmarks