diff --git a/primitive-unlifted.cabal b/primitive-unlifted.cabal
--- a/primitive-unlifted.cabal
+++ b/primitive-unlifted.cabal
@@ -1,6 +1,6 @@
 cabal-version: 2.2
 name: primitive-unlifted
-version: 0.1.0.0
+version: 0.1.1.0
 synopsis: Primitive GHC types with unlifted types inside
 homepage: https://github.com/andrewthad/primitive-unlifted
 bug-reports: https://github.com/andrewthad/primitive-unlifted/issues
diff --git a/src/Data/Primitive/Unlifted/Array.hs b/src/Data/Primitive/Unlifted/Array.hs
--- a/src/Data/Primitive/Unlifted/Array.hs
+++ b/src/Data/Primitive/Unlifted/Array.hs
@@ -65,6 +65,10 @@
   , foldrUnliftedArray'
   , foldlUnliftedArray
   , foldlUnliftedArray'
+  , foldlUnliftedArrayM'
+    -- * Traversals
+  , traverseUnliftedArray_
+  , itraverseUnliftedArray_
     -- * Mapping
   , mapUnliftedArray
   ) where
@@ -342,6 +346,41 @@
     go !i !acc
       | i < sz = go (i + 1) (f acc (indexUnliftedArray arr i))
       | otherwise = acc
+
+-- | Strict effectful left-associated fold over the elements of an 'UnliftedArray'.
+{-# INLINE foldlUnliftedArrayM' #-}
+foldlUnliftedArrayM' :: (PrimUnlifted a, Monad m)
+  => (b -> a -> m b) -> b -> UnliftedArray a -> m b
+foldlUnliftedArrayM' f z0 arr = go 0 z0
+  where
+    !sz = sizeofUnliftedArray arr
+    go !i !acc
+      | i < sz = f acc (indexUnliftedArray arr i) >>= go (i + 1) 
+      | otherwise = pure acc
+
+-- | Effectfully traverse the elements of an 'UnliftedArray', discarding
+-- the resulting values.
+{-# INLINE traverseUnliftedArray_ #-}
+traverseUnliftedArray_ :: (PrimUnlifted a, Applicative m)
+  => (a -> m b) -> UnliftedArray a -> m ()
+traverseUnliftedArray_ f arr = go 0
+  where
+    !sz = sizeofUnliftedArray arr
+    go !i
+      | i < sz = f (indexUnliftedArray arr i) *> go (i + 1) 
+      | otherwise = pure ()
+
+-- | Effectful indexed traversal of the elements of an 'UnliftedArray',
+-- discarding the resulting values.
+{-# INLINE itraverseUnliftedArray_ #-}
+itraverseUnliftedArray_ :: (PrimUnlifted a, Applicative m)
+  => (Int -> a -> m b) -> UnliftedArray a -> m ()
+itraverseUnliftedArray_ f arr = go 0
+  where
+    !sz = sizeofUnliftedArray arr
+    go !i
+      | i < sz = f i (indexUnliftedArray arr i) *> go (i + 1) 
+      | otherwise = pure ()
 
 -- | Map over the elements of an 'UnliftedArray'.
 {-# INLINE mapUnliftedArray #-}
diff --git a/src/Data/Primitive/Unlifted/Class.hs b/src/Data/Primitive/Unlifted/Class.hs
--- a/src/Data/Primitive/Unlifted/Class.hs
+++ b/src/Data/Primitive/Unlifted/Class.hs
@@ -6,6 +6,7 @@
   ( PrimUnlifted(..)
   ) where
 
+import Data.Primitive.PrimArray (PrimArray(..),MutablePrimArray(..))
 import Data.Primitive.ByteArray (ByteArray(..),MutableByteArray(..))
 import GHC.Exts (State#,MutableByteArray#,ByteArray#,Int#)
 import GHC.Exts (ArrayArray#,MutableArrayArray#,RuntimeRep(UnliftedRep))
@@ -33,6 +34,18 @@
     -> Int#
     -> a
 
+instance PrimUnlifted (PrimArray a) where
+  {-# inline writeUnliftedArray# #-}
+  {-# inline readUnliftedArray# #-}
+  {-# inline indexUnliftedArray# #-}
+  type Unlifted (PrimArray a) = ByteArray#
+  toUnlifted# (PrimArray x) = x
+  fromUnlifted# x = PrimArray x
+  writeUnliftedArray# a i (PrimArray x) = Exts.writeByteArrayArray# a i x
+  readUnliftedArray# a i s0 = case Exts.readByteArrayArray# a i s0 of
+    (# s1, x #) -> (# s1, PrimArray x #)
+  indexUnliftedArray# a i = PrimArray (Exts.indexByteArrayArray# a i)
+
 instance PrimUnlifted ByteArray where
   {-# inline writeUnliftedArray# #-}
   {-# inline readUnliftedArray# #-}
@@ -57,6 +70,19 @@
   readUnliftedArray# a i s0 = case Exts.readMutableByteArrayArray# a i s0 of
     (# s1, x #) -> (# s1, MutableByteArray (retoken x) #)
   indexUnliftedArray# a i = MutableByteArray (baToMba (Exts.indexByteArrayArray# a i))
+
+instance PrimUnlifted (MutablePrimArray s a) where
+  {-# inline writeUnliftedArray# #-}
+  {-# inline readUnliftedArray# #-}
+  {-# inline indexUnliftedArray# #-}
+  type Unlifted (MutablePrimArray s a) = MutableByteArray# s
+  toUnlifted# (MutablePrimArray x) = x
+  fromUnlifted# x = MutablePrimArray x
+  writeUnliftedArray# a i (MutablePrimArray x) =
+    Exts.writeMutableByteArrayArray# a i (retoken x)
+  readUnliftedArray# a i s0 = case Exts.readMutableByteArrayArray# a i s0 of
+    (# s1, x #) -> (# s1, MutablePrimArray (retoken x) #)
+  indexUnliftedArray# a i = MutablePrimArray (baToMba (Exts.indexByteArrayArray# a i))
 
 baToMba :: ByteArray# -> MutableByteArray# s
 {-# inline baToMba #-}