diff --git a/Numeric/MCMC/Metropolis.hs b/Numeric/MCMC/Metropolis.hs
--- a/Numeric/MCMC/Metropolis.hs
+++ b/Numeric/MCMC/Metropolis.hs
@@ -32,14 +32,13 @@
   ) where
 
 import Control.Monad (when)
-import Control.Monad.Primitive (PrimMonad, PrimState)
+import Control.Monad.Primitive (PrimMonad, PrimState, RealWorld)
 import Control.Monad.Trans.Class (lift)
 import Control.Monad.Trans.State.Strict (execStateT, get, put)
 import Data.Sampling.Types (Target(..), Chain(..), Transition)
 #if __GLASGOW_HASKELL__ < 710
 import Data.Traversable (Traversable, traverse)
 #endif
-import GHC.Prim (RealWorld)
 import Pipes (Producer, yield, (>->), runEffect)
 import qualified Pipes.Prelude as Pipes (mapM_, take)
 import System.Random.MWC.Probability (Gen, Prob)
diff --git a/mighty-metropolis.cabal b/mighty-metropolis.cabal
--- a/mighty-metropolis.cabal
+++ b/mighty-metropolis.cabal
@@ -1,5 +1,5 @@
 name:                mighty-metropolis
-version:             1.0.0
+version:             1.0.1
 synopsis:            The Metropolis algorithm.
 homepage:            http://github.com/jtobin/mighty-metropolis
 license:             MIT
@@ -38,7 +38,6 @@
       Numeric.MCMC.Metropolis
   build-depends:
       base             < 5
-    , ghc-prim
     , pipes
     , primitive
     , mcmc-types       >= 1.0.1