diff --git a/bench/Bench.hs b/bench/Bench.hs
new file mode 100644
--- /dev/null
+++ b/bench/Bench.hs
@@ -0,0 +1,52 @@
+{-# LANGUAGE TypeOperators #-}
+{-# LANGUAGE FlexibleContexts #-}
+{-# LANGUAGE FlexibleInstances #-}
+module Main ( main ) where
+
+import Control.Eff
+import Control.Eff.State.Strict
+import Control.Applicative
+import Control.DeepSeq
+import Control.Exception ( evaluate )
+import Control.Monad
+
+import Criterion
+import Criterion.Config
+import Criterion.Main
+
+import System.Random.Effect
+
+fastIntDist :: Member (State Random) r
+            => Int
+            -> Int
+            -> Eff r Int
+fastIntDist a' b' = do
+  let a = min a' b'
+      b = max a' b'
+      range = b - a
+
+  x <- randomInt
+  return (x `rem` range + a)
+{-# NOINLINE fastIntDist #-}
+
+instance NFData a => Benchmarkable (Eff (State Random :> ()) a) where
+  run eff n = do
+    let res = Control.Eff.run $ runRandomState (mkRandom 0) $ do
+                last <$> replicateM n eff
+
+    _ <- evaluate (rnf res)
+    return ()
+
+main :: IO ()
+main =
+  defaultMainWith config (return ()) [
+      bcompare [
+        bench "fastIntDist"    (fastIntDist    1 1000 :: Eff (State Random :> ()) Int)
+      , bench "uniformIntDist" (uniformIntDist 1 1000 :: Eff (State Random :> ()) Integer)
+      ]
+    ]
+  where
+    config = defaultConfig {
+    --  cfgPerformGC = ljust True
+     cfgConfInterval = ljust 0.99
+    }
diff --git a/src/System/Random/Effect.hs b/src/System/Random/Effect.hs
--- a/src/System/Random/Effect.hs
+++ b/src/System/Random/Effect.hs
@@ -77,8 +77,8 @@
 import qualified System.Random.Mersenne.Pure64 as SR
 
 import Control.Eff
-import Control.Eff.State
 import Control.Eff.Lift
+import Control.Eff.State.Strict
 
 -- | A pure mersenne twister pseudo-random number generator.
 data Random = Random {-# UNPACK #-} !SR.PureMT
@@ -92,7 +92,7 @@
 -- | Create a new random number generator, using the clocktime as the base for
 --   the seed. This must be called from a computation with a lifted base effect
 --   of 'IO'.
-mkRandomIO :: Member (Lift IO) r
+mkRandomIO :: SetMember Lift (Lift IO) r
            => Eff r Random
 mkRandomIO = lift (fmap Random SR.newPureMT)
 {-# INLINE mkRandomIO #-}
@@ -111,9 +111,9 @@
         => (SR.PureMT -> (a, SR.PureMT))
         -> Eff r a
 randomF f = do
-  (Random old) <- getState
+  (Random old) <- get
   let (val, new) = f old
-  putState (Random new)
+  put (Random new)
   return val
 {-# INLINE randomF #-}
 
diff --git a/system-random-effect.cabal b/system-random-effect.cabal
--- a/system-random-effect.cabal
+++ b/system-random-effect.cabal
@@ -1,14 +1,14 @@
-name:                system-random-effect
-version:             0.2.0
-synopsis:            Random number generation for extensible effects.
-homepage:            https://github.com/wowus/system-random-effect
-license:             BSD3
-license-file:        LICENSE
-author:              Clark Gaebel
-maintainer:          cgaebel@uwaterloo.ca
-category:            System
-build-type:          Simple
-cabal-version:       >=1.10
+name:                  system-random-effect
+version:               0.3.0
+synopsis:              Random number generation for extensible effects.
+homepage:              https://github.com/wowus/system-random-effect
+license:               BSD3
+license-file:          LICENSE
+author:                Clark Gaebel
+maintainer:            cgaebel@uwaterloo.ca
+category:              System
+build-type:            Simple
+cabal-version:         >=1.10
 
 library
   hs-source-dirs:      src/
@@ -16,7 +16,7 @@
   exposed-modules:     System.Random.Effect
 
   build-depends:       base == 4.6.*
-                     , extensible-effects == 1.1.*
+                     , extensible-effects == 1.2.*
                      , mersenne-random-pure64 == 0.2.*
                      , statistics == 0.10.*
                      , vector == 0.10.*
@@ -24,12 +24,12 @@
 
   default-language:    Haskell2010
 
-test-suite extensible-effects-tests
-  type: exitcode-stdio-1.0
-  main-is: Test.hs
-  hs-source-dirs: test/
+test-suite tests
+  type:                exitcode-stdio-1.0
+  main-is:             Test.hs
+  hs-source-dirs:      test/
 
-  ghc-options: -rtsopts=all -threaded
+  ghc-options:         -rtsopts=all -threaded
 
   build-depends:       base == 4.6.*
                      , QuickCheck == 2.*
@@ -37,11 +37,25 @@
                      , test-framework == 0.8.*
                      , test-framework-hunit == 0.3.*
                      , test-framework-quickcheck2 == 0.3.*
-                     , extensible-effects == 1.1.*
+                     , extensible-effects == 1.2.*
                      , system-random-effect
 
   default-language:    Haskell2010
 
+benchmark benchmarks
+  type:                exitcode-stdio-1.0
+  hs-source-dirs:      bench/
+  ghc-options:         -Wall -rtsopts=all -threaded -fno-warn-orphans -O2
+  main-is:             Bench.hs
+
+  build-depends:       base == 4.6.*
+                     , deepseq == 1.3.*
+                     , criterion == 0.8.*
+                     , extensible-effects == 1.2.*
+                     , system-random-effect
+
+  default-language:    Haskell2010
+
 source-repository head
-  type: git
-  location: https://github.com/wowus/system-random-effect
+  type:                git
+  location:            https://github.com/wowus/system-random-effect
diff --git a/test/Test.hs b/test/Test.hs
--- a/test/Test.hs
+++ b/test/Test.hs
@@ -3,7 +3,7 @@
 module Main ( main ) where
 
 import Control.Eff
-import Control.Eff.State
+import Control.Eff.State.Strict
 
 import System.Random.Effect
 
@@ -41,21 +41,32 @@
   let ddh = buildDDH xs
       minVal = 0
       maxVal = length xs - 1
-   in length xs == 0 || sum xs == 0 ||
+   in sum xs == 0 ||
         ((\x -> x >= minVal && x <= maxVal) . runWithSeed seed $
           discreteDist ddh)
 
 testNoZeroDiscreteDistributionPick :: [Word64] -> Word64 -> Bool
 testNoZeroDiscreteDistributionPick xs seed =
   let ddh = buildDDH xs
-      minVal = 0
-      maxVal = length xs - 1
-   in length xs == 0 || sum xs == 0 ||
+   in sum xs == 0 ||
         ((\x -> (xs !! x) /= 0) . runWithSeed seed $
           discreteDist ddh)
 
+testUnsafeThaw :: [Word64] -> Word64 -> Bool
+testUnsafeThaw xs seed =
+  let ddh = buildDDH xs
+   in sum xs == 0 ||
+        (runWithSeed seed $ do
+          _ <- discreteDist ddh
+          _ <- discreteDist ddh
+          _ <- discreteDist ddh
+          _ <- discreteDist ddh
+          _ <- discreteDist ddh
+          return True)
+
 tests =
   [ testProperty "random range" testUniformRandom
   , testProperty "discrete dist range" testDiscreteDistributionInRange
   , testProperty "no non-zero discrete dist pick" testNoZeroDiscreteDistributionPick
+  , testProperty "unsafeThaw is okay to use" testUnsafeThaw
   ]