diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,7 @@
+0.3
+---
+* Switched to `SipHash`, so the package actually works.
+
 0.2.3.2
 -------
 * More `#ifdef` bugfixes
diff --git a/hyperloglog.cabal b/hyperloglog.cabal
--- a/hyperloglog.cabal
+++ b/hyperloglog.cabal
@@ -1,6 +1,6 @@
 name:          hyperloglog
 category:      Numeric
-version:       0.2.3.3
+version:       0.3
 license:       BSD3
 cabal-version: >= 1.8
 license-file:  LICENSE
@@ -66,6 +66,7 @@
     semigroupoids             >= 4        && < 5,
     semigroups                >= 0.8.4    && < 1,
     safecopy                  >= 0.8.1    && < 0.9,
+    siphash                   >= 1.0.3    && < 2,
     tagged                    >= 0.4.5    && < 1,
     vector                    >= 0.9      && < 0.11
 
diff --git a/src/Data/HyperLogLog/Type.hs b/src/Data/HyperLogLog/Type.hs
--- a/src/Data/HyperLogLog/Type.hs
+++ b/src/Data/HyperLogLog/Type.hs
@@ -52,16 +52,19 @@
 import           Control.Applicative
 import           Control.Lens
 import           Control.Monad
+import           Crypto.MAC.SipHash
 import           Data.Approximate.Type
 import           Data.Bits
 import           Data.Bits.Extras
-import           Data.Hashable
+import           Data.Bytes.Put (runPutS)
+import           Data.Bytes.Serial
 import           Data.HyperLogLog.Config
 import           Data.Proxy
 import           Data.Semigroup
 import           Data.Serialize
 import qualified Data.Vector.Unboxed                           as V
 import qualified Data.Vector.Unboxed.Mutable                   as MV
+import           Data.Word
 import           Generics.Deriving                             hiding (D, to)
 import           GHC.Int
 
@@ -90,7 +93,7 @@
 -- Let's count a list of unique items and get the latest estimate:
 --
 -- >>> size (foldr insert mempty [1..10] :: HyperLogLog $(4))
--- Approximate {_confidence = 0.9972, _lo = 2, _estimate = 11, _hi = 20}
+-- Approximate {_confidence = 0.9972, _lo = 2, _estimate = 9, _hi = 17}
 --
 -- Note how 'insert' can be used to add new observations to the
 -- approximate counter.
@@ -129,12 +132,21 @@
   mappend = (<>)
   {-# INLINE mappend #-}
 
-insert :: (ReifiesConfig s, Hashable a) => a -> HyperLogLog s -> HyperLogLog s
+sipKey :: SipKey
+sipKey = SipKey 4 7
+
+siphash :: (Serial a) => a -> Word64
+siphash a = h
+  where !bs = runPutS (serialize a)
+        (SipHash !h) = hash sipKey bs
+{-# INLINE siphash #-}
+
+insert :: (ReifiesConfig s, Serial a) => a -> HyperLogLog s -> HyperLogLog s
 insert a m@(HyperLogLog v) = HyperLogLog $ V.modify (\x -> do
     old <- MV.read x bk
     when (rnk > old) $ MV.write x bk rnk
   ) v where
-  !h = w32 (hash a)
+  !h = w32 (siphash a)
   !bk = calcBucket m h
   !rnk = calcRank m h
 {-# INLINE insert #-}