diff --git a/online.cabal b/online.cabal
--- a/online.cabal
+++ b/online.cabal
@@ -1,11 +1,6 @@
--- This file has been generated from package.yaml by hpack version 0.28.2.
---
--- see: https://github.com/sol/hpack
---
--- hash: 23ad67040f06c24d3eb357c48f10a503d156cb1d8cf9ded5a9f749d497c3f937
-
+cabal-version: 2.0
 name:           online
-version:        0.3.0.0
+version:        0.4.0.0
 synopsis:       online statistics
 description:    transformation of statistics to online algorithms
 category:       statistics
@@ -17,34 +12,26 @@
 license:        BSD3
 license-file:   LICENSE
 build-type:     Simple
-cabal-version:  >= 1.10
-extra-source-files:
-    stack.yaml
 
 source-repository head
   type: git
   location: https://github.com/tonyday567/online
 
 library
+  exposed-modules:
+      Online
+      Online.Averages
+      Online.Medians
+      Online.Quantiles
   hs-source-dirs:
       src
-  default-extensions: NegativeLiterals NoImplicitPrelude OverloadedStrings UnicodeSyntax
   ghc-options: -Wall -Wcompat -Wincomplete-record-updates -Wincomplete-uni-patterns -Wredundant-constraints
   build-depends:
       base >=4.7 && <5
     , foldl
-    , numhask-prelude
-    , protolude
     , tdigest
     , vector
     , vector-algorithms
-  exposed-modules:
-      Online
-      Online.Averages
-      Online.Medians
-      Online.Quantiles
-  other-modules:
-      Paths_online
   default-language: Haskell2010
 
 test-suite test
@@ -52,12 +39,8 @@
   main-is: test.hs
   hs-source-dirs:
       test
-  default-extensions: NegativeLiterals NoImplicitPrelude OverloadedStrings UnicodeSyntax
   build-depends:
       base >=4.7 && <5
     , doctest
-    , protolude
     , tasty
-  other-modules:
-      Paths_online
   default-language: Haskell2010
diff --git a/src/Online/Averages.hs b/src/Online/Averages.hs
--- a/src/Online/Averages.hs
+++ b/src/Online/Averages.hs
@@ -1,5 +1,4 @@
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE NoImplicitPrelude #-}
 
 -- | online statistics based on a moving average
 module Online.Averages
@@ -21,7 +20,7 @@
 
 import qualified Control.Foldl as L
 import Control.Foldl (Fold(..))
-import NumHask.Prelude
+import Prelude
 
 -- | Most common statistics are averages.
 newtype Averager a b = Averager
@@ -37,18 +36,16 @@
   mappend = (<>)
 
 -- | online takes a function and turns it into a `Control.Foldl.Fold` where the step is an incremental update of the (isomorphic) statistic.
-online :: (Field b) => (a -> b) -> (b -> b) -> Fold a b
+online :: (Fractional b) => (a -> b) -> (b -> b) -> Fold a b
 online f g = Fold step begin extract
   where
-    begin = Averager (zero, zero)
-    step (Averager (s, c)) a = Averager (g $ s + f a, g $ c + one)
+    begin = Averager (0, 0)
+    step (Averager (s, c)) a = Averager (g $ s + f a, g $ c + 1)
     extract (Averager (s, c)) = s / c
 {-# INLINABLE online #-}
 
 -- $setup
 --
--- >>> :set -XNoImplicitPrelude
--- >>> import NumHask.Prelude
 -- >>> import qualified Control.Foldl as L
 -- >>> let n = 100
 -- >>> let r = 0.9
@@ -60,23 +57,23 @@
 -- >>> L.fold (ma 1) [0..100]
 -- 50.0
 --
--- >>> L.fold (ma 1e-12) [0..100] ≈ 100
--- True
+-- >>> L.fold (ma 1e-12) [0..100]
+-- 99.999999999999
 --
 -- >>> L.fold (ma 0.9) [0..100]
 -- 91.00241448887785
 --
-ma :: (Field a) => a -> Fold a a
-ma r = online identity (* r)
+ma :: (Fractional a) => a -> Fold a a
+ma r = online id (* r)
 {-# INLINABLE ma #-}
 
 -- | absolute average
-absma :: (Field a, Signed a) => a -> Fold a a
+absma :: (Fractional a) => a -> Fold a a
 absma r = online abs (* r)
 {-# INLINABLE absma #-}
 
 -- | average square
-sqma :: (Field a) => a -> Fold a a
+sqma :: (Fractional a) => a -> Fold a a
 sqma r = online (\x -> x * x) (* r)
 {-# INLINABLE sqma #-}
 
@@ -95,20 +92,20 @@
 --
 -- >>> L.fold (std 0.99) [0..1000]
 -- 99.28328803164005
-std :: (ExpField a) => a -> Fold a a
-std r = (\s ss -> sqrt (ss - s ** (one+one))) <$> ma r <*> sqma r
+std :: (Fractional a, Floating a) => a -> Fold a a
+std r = (\s ss -> sqrt (ss - s ** 2)) <$> ma r <*> sqma r
 {-# INLINABLE std #-}
 
 -- | the covariance of a tuple
 -- given an underlying central tendency fold
-cov :: (Field a) => Fold a a -> Fold (a, a) a
+cov :: (Num a) => Fold a a -> Fold (a, a) a
 cov m =
   (\xy x' y' -> xy - x' * y') <$> L.premap (uncurry (*)) m <*> L.premap fst m <*>
   L.premap snd m
 {-# INLINABLE cov #-}
 
 -- | correlation of a tuple, specialised to Guassian
-corrGauss :: (ExpField a) => a -> Fold (a, a) a
+corrGauss :: (Floating a) => a -> Fold (a, a) a
 corrGauss r =
   (\cov' stdx stdy -> cov' / (stdx * stdy)) <$> cov (ma r) <*>
   L.premap fst (std r) <*>
@@ -116,7 +113,7 @@
 {-# INLINABLE corrGauss #-}
 
 -- | a generalised version of correlation of a tuple
-corr :: (Field a) => Fold a a -> Fold a a -> Fold (a, a) a
+corr :: (Floating a) => Fold a a -> Fold a a -> Fold (a, a) a
 corr central deviation =
   (\cov' stdx stdy -> cov' / (stdx * stdy)) <$> cov central <*>
   L.premap fst deviation <*>
@@ -125,7 +122,7 @@
 
 -- | the beta in a simple linear regression of a tuple
 -- given an underlying central tendency fold
-beta :: (Field a) => Fold a a -> Fold (a, a) a
+beta :: (Fractional a) => Fold a a -> Fold (a, a) a
 beta m =
   (\xy x' y' x2 -> (xy - x' * y') / (x2 - x' * x')) <$> L.premap (uncurry (*)) m <*>
   L.premap fst m <*>
@@ -134,7 +131,7 @@
 {-# INLINABLE beta #-}
 
 -- | the alpha of a tuple
-alpha :: (Field a) => Fold a a -> Fold (a, a) a
+alpha :: (Fractional a) => Fold a a -> Fold (a, a) a
 alpha m = (\y b x -> y - b * x) <$> L.premap fst m <*> beta m <*> L.premap snd m
 {-# INLINABLE alpha #-}
 
diff --git a/src/Online/Medians.hs b/src/Online/Medians.hs
--- a/src/Online/Medians.hs
+++ b/src/Online/Medians.hs
@@ -16,7 +16,7 @@
 
 import qualified Control.Foldl as L
 import Control.Foldl (Fold(..))
-import Protolude
+import Prelude
 
 -- | A rough Median.
 -- The average absolute value of the stat is used to callibrate estimate drift towards the median
@@ -56,8 +56,6 @@
 
 -- $setup
 --
--- >>> :set -XNoImplicitPrelude
--- >>> import NumHask.Prelude
 -- >>> import qualified Control.Foldl as L
 -- >>> let n = 100
 -- >>> let inc = 0.1
@@ -69,12 +67,12 @@
 -- 93.92822312742108
 --
 maL1 :: (Ord a, Fractional a) => a -> a -> a -> Fold a a
-maL1 i d r = onlineL1 i d identity (* r)
+maL1 i d r = onlineL1 i d id (* r)
 {-# INLINABLE maL1 #-}
 
 -- | moving absolute deviation
 absmaL1 :: (Ord a, Fractional a) => a -> a -> a -> Fold a a
-absmaL1 i d r = fst <$> onlineL1' i d identity (* r)
+absmaL1 i d r = fst <$> onlineL1' i d id (* r)
 {-# INLINABLE absmaL1 #-}
 
 -- | covariance of a tuple
diff --git a/src/Online/Quantiles.hs b/src/Online/Quantiles.hs
--- a/src/Online/Quantiles.hs
+++ b/src/Online/Quantiles.hs
@@ -20,7 +20,11 @@
 import Data.TDigest.Postprocess (HistBin, histogram)
 import qualified Data.Vector.Algorithms.Heap as VHeap
 import qualified Data.Vector.Unboxed as VU
-import NumHask.Prelude
+import Prelude
+import Control.Monad.ST (runST)
+import Data.Maybe
+import Data.Ord
+import Data.Foldable
 
 -- | a raw non-online tdigest fold
 tDigest :: L.Fold Double (TDigest 25)
@@ -28,7 +32,7 @@
   where
     step x a = insert a x
     begin = tdigest ([] :: [Double]) :: TDigest 25
-    done = identity
+    done = id
 
 -- | non-online version
 tDigestQuantiles :: [Double] -> L.Fold Double [Double]
@@ -36,7 +40,7 @@
   where
     step x a = insert a x
     begin = tdigest ([] :: [Double]) :: TDigest 25
-    done x = fromMaybe nan . (`quantile` compress x) <$> qs
+    done x = fromMaybe (0/0) . (`quantile` compress x) <$> qs
 
 -- | non-online version
 tDigestHist :: L.Fold Double (Maybe (NonEmpty HistBin))
@@ -61,7 +65,7 @@
   where
     step x a = onlineInsert a x
     begin = emptyOnlineTDigest r
-    done x = fromMaybe nan . (`quantile` t) <$> qs
+    done x = fromMaybe (0/0) . (`quantile` t) <$> qs
       where
         (OnlineTDigest t _ _) = onlineForceCompress x
 
@@ -70,14 +74,14 @@
   where
     step x a = onlineInsert a x
     begin = emptyOnlineTDigest r
-    done x = fromMaybe nan (quantile 0.5 t)
+    done x = fromMaybe (0/0) (quantile 0.5 t)
       where
         (OnlineTDigest t _ _) = onlineForceCompress x
 
 onlineInsert' :: Double -> OnlineTDigest -> OnlineTDigest
 onlineInsert' x (OnlineTDigest td' n r) =
   OnlineTDigest
-    (insertCentroid (x, r ^^ (-(fromIntegral $ n + 1))) td')
+    (insertCentroid (x, r ^^ (-(fromIntegral $ n + 1) :: Integer)) td')
     (n + 1)
     r
 
@@ -98,8 +102,8 @@
 onlineForceCompress (OnlineTDigest t n r) = OnlineTDigest t' 0 r
   where
     t' =
-      NumHask.Prelude.foldl' (flip insertCentroid) emptyTDigest $
-      (\(m, w) -> (m, w * (r ^^ fromIntegral n))) . fst <$> VU.toList centroids
+      foldl' (flip insertCentroid) emptyTDigest $
+      (\(m, w) -> (m, w * (r ^^ n))) . fst <$> VU.toList centroids
     -- Centroids are shuffled based on space
     centroids :: VU.Vector (Centroid, Double)
     centroids =
@@ -107,17 +111,16 @@
         v <- toMVector t
         -- sort by cumulative weight
         VHeap.sortBy (comparing snd) v
-        f <- VU.unsafeFreeze v
-        pure f
+        VU.unsafeFreeze v
 
 onlineDigitize :: Double -> [Double] -> L.Fold Double Int
 onlineDigitize r qs = L.Fold step begin done
   where
     step (x, _) a = (onlineInsert a x, a)
-    begin = (emptyOnlineTDigest r, nan)
+    begin = (emptyOnlineTDigest r, 0/0)
     done (x, l) = bucket' qs' l
       where
-        qs' = fromMaybe nan . (`quantile` t) <$> qs
+        qs' = fromMaybe (0/0) . (`quantile` t) <$> qs
         (OnlineTDigest t _ _) = onlineForceCompress x
         bucket' xs l' =
           L.fold L.sum $
diff --git a/stack.yaml b/stack.yaml
deleted file mode 100644
--- a/stack.yaml
+++ /dev/null
@@ -1,8 +0,0 @@
-resolver: nightly-2018-06-02
-
-packages:
-  - .
-
-extra-deps: []
-
-# allow-newer: true
diff --git a/test/test.hs b/test/test.hs
--- a/test/test.hs
+++ b/test/test.hs
@@ -2,7 +2,7 @@
 
 module Main where
 
-import Protolude
+import Prelude
 import Test.Tasty (TestTree, testGroup, defaultMain)
 import Test.DocTest