diff --git a/benchmark/Speed.hs b/benchmark/Speed.hs
index 0d72808c..ac9fa0d5 100644
--- a/benchmark/Speed.hs
+++ b/benchmark/Speed.hs
@@ -4,7 +4,8 @@
 
 module Main (main) where
 
-import Control.Monad.Bayes.Class (MonadMeasure)
+import Control.Monad (replicateM)
+import Control.Monad.Bayes.Class (MonadMeasure, normal)
 import Control.Monad.Bayes.Inference.MCMC (MCMCConfig (MCMCConfig, numBurnIn, numMCMCSteps, proposal), Proposal (SingleSiteMH))
 import Control.Monad.Bayes.Inference.RMSMC (rmsmcDynamic)
 import Control.Monad.Bayes.Inference.SMC (SMCConfig (SMCConfig, numParticles, numSteps, resampler), smc)
@@ -136,12 +137,21 @@ samplesBenchmarks lrData hmmData ldaData = benchmarks
           m <- models
           return (s, m, a)
 
+normalBenchmarks :: [Benchmark]
+normalBenchmarks = [ bench "Normal single sample monad bayes" $ nfIO $ do
+                       sampleIOfixed (do xs <- replicateM 1000 $ normal 0.0 1.0
+                                         return $ sum xs)
+                   ]
+
 speedLengthCSV :: FilePath
 speedLengthCSV = "speed-length.csv"
 
 speedSamplesCSV :: FilePath
 speedSamplesCSV = "speed-samples.csv"
 
+normalSamplesCSV :: FilePath
+normalSamplesCSV = "normal-samples.csv"
+
 rawDAT :: FilePath
 rawDAT = "raw.dat"
 
@@ -158,12 +168,14 @@ removeIfExists file = do
 
 main :: IO ()
 main = do
-  cleanupLastRun
-  lrData <- sampleIOfixed (LogReg.syntheticData 1000)
-  hmmData <- sampleIOfixed (HMM.syntheticData 1000)
-  ldaData <- sampleIOfixed (LDA.syntheticData 5 1000)
-  let configLength = defaultConfig {csvFile = Just speedLengthCSV, rawDataFile = Just rawDAT}
-  defaultMainWith configLength (lengthBenchmarks lrData hmmData ldaData)
-  let configSamples = defaultConfig {csvFile = Just speedSamplesCSV, rawDataFile = Just rawDAT}
-  defaultMainWith configSamples (samplesBenchmarks lrData hmmData ldaData)
-  void $ runProcess "python plots.py"
+  -- cleanupLastRun
+  -- lrData <- sampleIOfixed (LogReg.syntheticData 1000)
+  -- hmmData <- sampleIOfixed (HMM.syntheticData 1000)
+  -- ldaData <- sampleIOfixed (LDA.syntheticData 5 1000)
+  -- let configLength = defaultConfig {csvFile = Just speedLengthCSV, rawDataFile = Just rawDAT}
+  -- defaultMainWith configLength (lengthBenchmarks lrData hmmData ldaData)
+  -- let configSamples = defaultConfig {csvFile = Just speedSamplesCSV, rawDataFile = Just rawDAT}
+  -- defaultMainWith configSamples (samplesBenchmarks lrData hmmData ldaData)
+  let configNormal = defaultConfig {csvFile = Just normalSamplesCSV, rawDataFile = Just rawDAT}
+  defaultMainWith configNormal normalBenchmarks
+  -- void $ runProcess "python plots.py"
diff --git a/monad-bayes.cabal b/monad-bayes.cabal
index c576c005..4fed4d5c 100644
--- a/monad-bayes.cabal
+++ b/monad-bayes.cabal
@@ -57,6 +57,7 @@ common deps
     , pretty-simple    ^>=4.1
     , primitive        >=0.7     && <0.9
     , random           ^>=1.2
+    , random-fu
     , safe             ^>=0.3.17
     , scientific       ^>=0.3
     , statistics       >=0.14.0  && <0.17
diff --git a/shell.nix b/shell.nix
index e6d91731..c19e7938 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,14 +1,67 @@
-(
-  import
-  (
-    let
-      lock = builtins.fromJSON (builtins.readFile ./flake.lock);
-    in
-      fetchTarball {
-        url = "https://github.com/edolstra/flake-compat/archive/${lock.nodes.flake-compat.locked.rev}.tar.gz";
-        sha256 = lock.nodes.flake-compat.locked.narHash;
-      }
-  )
-  {src = ./.;}
-)
-.shellNix
+{ nixpkgs ? import <nixpkgs> {}, compiler ? "default", doBenchmark ? false }:
+
+let
+
+  inherit (nixpkgs) pkgs;
+
+  f = { mkDerivation, abstract-par, base, brick, containers
+      , criterion, directory, foldl, free, histogram-fill, hspec, ieee754
+      , integration, lens, lib, linear, log-domain, math-functions
+      , matrix, monad-coroutine, monad-extras, mtl, mwc-random
+      , optparse-applicative, pipes, pretty-simple, primitive, process
+      , QuickCheck, random, random-fu, safe, scientific, statistics, text, time
+      , transformers, typed-process, vector, vty
+      }:
+      mkDerivation {
+        pname = "monad-bayes";
+        version = "1.2.0";
+        src = ./.;
+        isLibrary = true;
+        isExecutable = true;
+        libraryHaskellDepends = [
+          base brick containers foldl free histogram-fill ieee754 integration
+          lens linear log-domain math-functions matrix monad-coroutine
+          monad-extras mtl mwc-random pipes pretty-simple primitive random random-fu
+          safe scientific statistics text vector vty
+        ];
+        executableHaskellDepends = [
+          abstract-par base brick containers criterion directory foldl free
+          histogram-fill hspec ieee754 integration lens linear log-domain
+          math-functions matrix monad-coroutine monad-extras mtl mwc-random
+          optparse-applicative pipes pretty-simple primitive process
+          QuickCheck random random-fu safe scientific statistics text time transformers
+          typed-process vector vty
+        ];
+        testHaskellDepends = [
+          abstract-par base brick containers criterion directory foldl free
+          histogram-fill hspec ieee754 integration lens linear log-domain
+          math-functions matrix monad-coroutine monad-extras mtl mwc-random
+          optparse-applicative pipes pretty-simple primitive process
+          QuickCheck random random-fu safe scientific statistics text time transformers
+          typed-process vector vty
+        ];
+        benchmarkHaskellDepends = [
+          abstract-par base brick containers criterion directory foldl free
+          histogram-fill hspec ieee754 integration lens linear log-domain
+          math-functions matrix monad-coroutine monad-extras mtl mwc-random
+          optparse-applicative pipes pretty-simple primitive process
+          QuickCheck random random-fu safe scientific statistics text time transformers
+          typed-process vector vty
+        ];
+        homepage = "http://github.com/tweag/monad-bayes#readme";
+        description = "A library for probabilistic programming";
+        license = lib.licenses.mit;
+        mainProgram = "example";
+      };
+
+  haskellPackages = if compiler == "default"
+                       then pkgs.haskellPackages
+                       else pkgs.haskell.packages.${compiler};
+
+  variant = if doBenchmark then pkgs.haskell.lib.doBenchmark else pkgs.lib.id;
+
+  drv = variant (haskellPackages.callPackage f {});
+
+in
+
+  if pkgs.lib.inNixShell then drv.env else drv
diff --git a/src/Control/Monad/Bayes/Sampler/Strict.hs b/src/Control/Monad/Bayes/Sampler/Strict.hs
index f5f9b645..61dd2457 100644
--- a/src/Control/Monad/Bayes/Sampler/Strict.hs
+++ b/src/Control/Monad/Bayes/Sampler/Strict.hs
@@ -44,8 +44,19 @@ import Control.Monad.Reader (MonadIO, ReaderT (..))
 import Control.Monad.ST (ST)
 import Numeric.Log (Log (ln))
 import System.Random.MWC.Distributions qualified as MWC
+import Data.Random qualified as RF
+import Data.Random.Distribution qualified as RF
+import Data.Random.Distribution.Normal qualified as RF
+import Data.Random.Distribution.Gamma qualified as RF
+import Data.Random.Distribution.Beta qualified as RF
+import Data.Random.Distribution.Bernoulli qualified as RF
+import Data.Random.Distribution.Uniform as RF
 import System.Random.Stateful (IOGenM (..), STGenM, StatefulGen, StdGen, initStdGen, mkStdGen, newIOGenM, newSTGenM, uniformDouble01M, uniformRM)
 
+import Control.Monad.State
+import           System.Random.Stateful
+import Control.Monad.Reader.Class
+
 -- | The sampling interpretation of a probabilistic program
 -- Here m is typically IO or ST
 newtype SamplerT g m a = SamplerT {runSamplerT :: ReaderT g m a} deriving (Functor, Applicative, Monad, MonadIO)
@@ -58,17 +69,17 @@ type SamplerIO = SamplerT (IOGenM StdGen) IO
 -- to particular pairs of monad and RNG
 type SamplerST s = SamplerT (STGenM StdGen s) (ST s)
 
-instance (StatefulGen g m) => MonadDistribution (SamplerT g m) where
-  random = SamplerT (ReaderT uniformDouble01M)
+instance StatefulGen g m => MonadDistribution (SamplerT g m) where
+  random = SamplerT (ReaderT $ RF.runRVar $ RF.stdUniform)
 
-  uniform a b = SamplerT (ReaderT $ uniformRM (a, b))
-  normal m s = SamplerT (ReaderT (MWC.normal m s))
-  gamma shape scale = SamplerT (ReaderT $ MWC.gamma shape scale)
-  beta a b = SamplerT (ReaderT $ MWC.beta a b)
+  uniform a b = SamplerT (ReaderT $ RF.runRVar $ RF.doubleUniform a b)
+  normal m s = SamplerT (ReaderT $ RF.runRVar $ RF.normal m s)
+  gamma shape scale = SamplerT (ReaderT $ RF.runRVar $ RF.gamma shape scale)
+  beta a b = SamplerT (ReaderT $ RF.runRVar $ RF.beta a b)
 
-  bernoulli p = SamplerT (ReaderT $ MWC.bernoulli p)
-  categorical ps = SamplerT (ReaderT $ MWC.categorical ps)
-  geometric p = SamplerT (ReaderT $ MWC.geometric0 p)
+  bernoulli p = SamplerT (ReaderT $ RF.runRVar $ RF.bernoulli p)
+  -- categorical ps = error "categorical"
+  -- geometric p = error "geometric"
 
 -- | Sample with a random number generator of your choice e.g. the one
 -- from `System.Random`.