diff --git a/ChangeLog b/ChangeLog
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Changes in 0.13.3.1
+
+  * primitive-0.6 compatibility
+
+
 Changes in 0.13.3.0
 
   * Monadic variant of vector shuffle added: `uniformShuffleM`
diff --git a/System/Random/MWC.hs b/System/Random/MWC.hs
--- a/System/Random/MWC.hs
+++ b/System/Random/MWC.hs
@@ -99,6 +99,9 @@
 
 import Control.Monad           (ap, liftM, unless)
 import Control.Monad.Primitive (PrimMonad, PrimState, unsafePrimToIO)
+#if MIN_VERSION_primitive(0,6,0)
+import Control.Monad.Primitive (PrimBase)
+#endif
 import Control.Monad.ST        (ST)
 import Data.Bits               (Bits, (.&.), (.|.), shiftL, shiftR, xor)
 import Data.Int                (Int8, Int16, Int32, Int64)
@@ -428,7 +431,13 @@
 -- Cryptographic API as a source of random numbers (it uses the system
 -- clock instead). As a result, the sequences it generates may not be
 -- highly independent.
-withSystemRandom :: PrimMonad m => (Gen (PrimState m) -> m a) -> IO a
+withSystemRandom ::
+#if MIN_VERSION_primitive(0,6,0)
+                    PrimBase m
+#else
+                    PrimMonad m
+#endif
+                 => (Gen (PrimState m) -> m a) -> IO a
 withSystemRandom act = do
   seed <- acquireSeedSystem `E.catch` \(_::E.IOException) -> do
     seen <- atomicModifyIORef warned ((,) True)
diff --git a/System/Random/MWC/Distributions.hs b/System/Random/MWC/Distributions.hs
--- a/System/Random/MWC/Distributions.hs
+++ b/System/Random/MWC/Distributions.hs
@@ -41,7 +41,7 @@
 import Control.Monad.Primitive (PrimMonad, PrimState)
 import Data.Bits ((.&.))
 import Data.Foldable (foldl')
-import Data.Traversable (Traversable,mapM)
+import Data.Traversable (mapM)
 import Data.Word (Word32)
 import System.Random.MWC (Gen, uniform, uniformR)
 import qualified Data.Vector.Unboxed         as I
diff --git a/mwc-random.cabal b/mwc-random.cabal
--- a/mwc-random.cabal
+++ b/mwc-random.cabal
@@ -1,5 +1,5 @@
 name:           mwc-random
-version:        0.13.3.0
+version:        0.13.3.1
 synopsis:       Fast, high quality pseudo random number generation
 description:
   This package contains code for generating high quality random