diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,3 +1,7 @@
+## 0.1.2.0
+
+* Added PRef
+
 ## 0.1.1.0
 
 * Added reference benchmark.
diff --git a/Data/Mutable/PRef.hs b/Data/Mutable/PRef.hs
new file mode 100644
--- /dev/null
+++ b/Data/Mutable/PRef.hs
@@ -0,0 +1,58 @@
+{-# LANGUAGE MagicHash    #-}
+{-# LANGUAGE TypeFamilies #-}
+-- | Use @ByteArray@s containing one element for mutable references.
+--
+-- This is similar to @URef@s, but avoids the overhead of storing the length of
+-- the @Vector@, which we statically know will always be 1. This allows it to
+-- be a bit faster.
+--
+-- Motivated by: <http://stackoverflow.com/questions/27261813/why-is-my-little-stref-int-require-allocating-gigabytes> and ArrayRef.
+module Data.Mutable.PRef
+    ( -- * Types
+      PRef
+    , IOPRef
+      -- * Functions
+    , asPRef
+    , MutableRef (..)
+    ) where
+
+import Control.Monad            (liftM)
+import Data.Mutable.Class
+import Data.Primitive.ByteArray
+import Data.Primitive.Types
+import GHC.Types                (Int (..))
+
+-- | A primitive ByteArray reference, supporting any monad.
+newtype PRef s a = PRef (MutableByteArray s)
+
+asPRef :: PRef s a -> PRef s a
+asPRef x = x
+{-# INLINE asPRef #-}
+
+-- | A primitive ByteArray IO reference.
+type IOPRef = PRef (PrimState IO)
+
+instance MutableContainer (PRef s a) where
+    type MCState (PRef s a) = s
+instance Prim a => MutableRef (PRef s a) where
+    type RefElement (PRef s a) = a
+
+    newRef x = do
+        ba <- newByteArray (I# (sizeOf# x))
+        writeByteArray ba 0 x
+        return $! PRef ba
+    {-# INLINE newRef #-}
+
+    readRef (PRef ba) = readByteArray ba 0
+    {-# INLINE readRef #-}
+
+    writeRef (PRef ba) = writeByteArray ba 0
+    {-# INLINE writeRef #-}
+
+    modifyRef (PRef ba) f = do
+        x <- readByteArray ba 0
+        writeByteArray ba 0 $! f x
+    {-# INLINE modifyRef #-}
+
+    modifyRef' = modifyRef
+    {-# INLINE modifyRef' #-}
diff --git a/bench/ref.hs b/bench/ref.hs
--- a/bench/ref.hs
+++ b/bench/ref.hs
@@ -4,6 +4,7 @@
 import Data.Mutable.Class
 import Data.Mutable.SRef
 import Data.Mutable.URef
+import Data.Mutable.PRef
 import Data.Mutable.VRef
 
 test :: (MCState c ~ PrimState IO, RefElement c ~ Int, MutableRef c)
@@ -27,6 +28,7 @@
     , test "STRef" asSTRef
     , test "MutVar" asMutVar
     , test "URef" asURef
+    , test "PRef" asPRef
     , test "SRef" asSRef
     , test "VRef" asVRef
     ]
diff --git a/mutable-containers.cabal b/mutable-containers.cabal
--- a/mutable-containers.cabal
+++ b/mutable-containers.cabal
@@ -1,5 +1,5 @@
 name:                mutable-containers
-version:             0.1.1.0
+version:             0.1.2.0
 synopsis:            Abstactions and concrete implementations of mutable containers
 description:         See docs and README at <http://www.stackage.org/package/mutable-containers>
 homepage:            https://github.com/fpco/mutable-containers
@@ -16,6 +16,7 @@
   exposed-modules:     Data.Mutable.SRef
                        Data.Mutable.Class
                        Data.Mutable.URef
+                       Data.Mutable.PRef
                        Data.Mutable.VRef
                        Data.Mutable.DList
                        Data.Mutable.Deque
@@ -24,6 +25,7 @@
                      , containers
                      , vector
                      , mono-traversable
+                     , ghc-prim
   default-language:    Haskell2010
 
 test-suite test
diff --git a/test/Spec.hs b/test/Spec.hs
--- a/test/Spec.hs
+++ b/test/Spec.hs
@@ -4,6 +4,7 @@
 import Data.Mutable.DList
 import Data.Mutable.SRef
 import Data.Mutable.URef
+import Data.Mutable.PRef
 import Data.Mutable.VRef
 import Data.Sequence             (Seq)
 import Data.Vector               (Vector)
@@ -111,6 +112,7 @@
                         _ <- atomic' tested $ \x -> (x - i, ())
                         check
         test "URef" asURef modifyRefHelper modifyRefHelper'
+        test "PRef" asPRef modifyRefHelper modifyRefHelper'
         test "SRef" asSRef modifyRefHelper modifyRefHelper'
         test "VRef" asVRef modifyRefHelper modifyRefHelper'
         test "STRef" asSTRef modifyRefHelper modifyRefHelper'