diff --git a/Data/Vector/Storable/MMap.hs b/Data/Vector/Storable/MMap.hs
--- a/Data/Vector/Storable/MMap.hs
+++ b/Data/Vector/Storable/MMap.hs
@@ -1,8 +1,10 @@
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeFamilies #-}
 module Data.Vector.Storable.MMap (
   System.IO.MMap.Mode(..),
   unsafeMMapMVector,
-  unsafeMMapVector
+  unsafeMMapVector,
+  writeMMapVector
 ) where
 
 import System.IO.MMap
@@ -10,12 +12,17 @@
 
 import qualified Data.Vector.Storable as I
 import qualified Data.Vector.Storable.Mutable as M
+
+import qualified Data.Vector.Generic as G
+
+
 import Data.Int
 
+import Control.Monad
 import Control.Monad.Primitive
 
 -- | Map a file into memory as a mutable vector.
-unsafeMMapMVector :: forall s a. Storable a => FilePath -- ^ Path of the file to map
+unsafeMMapMVector :: forall a. Storable a => FilePath -- ^ Path of the file to map
                                             -> Mode -- ^ Mapping mode
                                             -> Maybe (Int64, Int) -- ^ 'Nothing' to map entire file into memory, otherwise 'Just (fileOffset, elementCount)'
                                             -> IO (M.MVector (PrimState IO) a)
@@ -36,3 +43,18 @@
           Nothing -> Nothing
           Just (start, length) -> Just (start, length * sizeOf (undefined :: a))
      return $ I.unsafeFromForeignPtr foreignPtr offset (size `div` sizeOf (undefined :: a))
+
+
+-- | Write a file from a vector
+-- Be careful with existing files, parts behind the mapped range will stay
+-- as they are before the write operation.
+writeMMapVector :: forall v a. (Storable a, G.Vector v a) 
+                => FilePath -- ^ Path of the file to map
+                -> v a      -- ^ Vector to write
+                -> IO ()
+writeMMapVector path src = do
+    let len = G.length src
+    target <- unsafeMMapMVector path ReadWriteEx (Just (0,len))
+    I.copy target (G.convert src)
+
+{-# INLINABLE writeMMapVector #-}
diff --git a/test/TestSuite.hs b/test/TestSuite.hs
new file mode 100644
--- /dev/null
+++ b/test/TestSuite.hs
@@ -0,0 +1,27 @@
+
+
+
+
+module Main where
+
+import           Test.QuickCheck
+import           Test.QuickCheck.Monadic
+
+import qualified Data.Vector.Storable as V
+import qualified Data.Vector.Storable.MMap as V
+
+import           System.IO.Temp
+
+
+prop_read_write :: [Double] -> Property
+prop_read_write l = monadicIO $ do
+    let v = V.fromList l
+
+    v' <- run $ withSystemTempFile "vector-mmap-" $ \fn _ -> do
+      _ <- V.writeMMapVector fn v
+      V.unsafeMMapVector fn Nothing
+
+    assert (v == v')
+
+
+main = quickCheck prop_read_write
diff --git a/vector-mmap.cabal b/vector-mmap.cabal
--- a/vector-mmap.cabal
+++ b/vector-mmap.cabal
@@ -1,5 +1,5 @@
 Name:           vector-mmap
-Version:        0.0.2
+Version:        0.0.3
 License:        BSD3
 License-File:   LICENSE
 Author:         Daniel Peebles <pumpkingod@gmail.com>
@@ -11,7 +11,7 @@
 Description:
         Memory map immutable and mutable vectors.
 
-Cabal-Version:  >= 1.2
+Cabal-Version:  >= 1.8
 Build-Type:     Simple
 
 Library
@@ -19,3 +19,15 @@
         Data.Vector.Storable.MMap
 
   Build-Depends: base >= 2 && < 5, mmap >= 0.5.4, vector >= 0.5, primitive >= 0.2.1
+
+
+Test-Suite quickcheck
+  Type: exitcode-stdio-1.0
+  HS-Source-Dirs: test
+  Main-is: TestSuite.hs
+  build-depends: base >= 2 && < 5, vector-mmap, vector, QuickCheck, temporary
+
+
+Source-Repository head
+  Type: git
+  Location: https://github.com/copumpkin/vector-mmap