diff --git a/Data/Conduit/Binary.hs b/Data/Conduit/Binary.hs
--- a/Data/Conduit/Binary.hs
+++ b/Data/Conduit/Binary.hs
@@ -10,6 +10,7 @@
       -- ** Sources
       sourceFile
     , sourceHandle
+    , sourceHandleUnsafe
     , sourceIOHandle
     , sourceFileRange
     , sourceHandleRange
@@ -43,7 +44,7 @@
 import Data.Conduit
 import Data.Conduit.List (sourceList, consume)
 import Control.Exception (assert, finally)
-import Control.Monad (unless)
+import Control.Monad (unless, when)
 import Control.Monad.IO.Class (liftIO, MonadIO)
 import Control.Monad.Trans.Resource (allocate, release)
 import Control.Monad.Trans.Class (lift)
@@ -62,6 +63,7 @@
 import Foreign.ForeignPtr (touchForeignPtr)
 import Foreign.Ptr (plusPtr)
 import Foreign.Storable (peek)
+import GHC.ForeignPtr           (mallocPlainForeignPtrBytes)
 
 -- | Stream the contents of a file as binary data.
 --
@@ -97,6 +99,31 @@
         if S.null bs
             then return ()
             else yield bs >> loop
+
+-- | Same as @sourceHandle@, but instead of allocating a new buffer for each
+-- incoming chunk of data, reuses the same buffer. Therefore, the @ByteString@s
+-- yielded by this function are not referentially transparent between two
+-- different @yield@s.
+--
+-- This function will be slightly more efficient than @sourceHandle@ by
+-- avoiding allocations and reducing garbage collections, but should only be
+-- used if you can guarantee that you do not reuse a @ByteString@ (or any slice
+-- thereof) between two calls to @await@.
+--
+-- Since 1.0.12
+sourceHandleUnsafe :: MonadIO m => IO.Handle -> Source m ByteString
+sourceHandleUnsafe handle = do
+    fptr <- liftIO $ mallocPlainForeignPtrBytes defaultChunkSize
+    let ptr = unsafeForeignPtrToPtr fptr
+        loop = do
+            count <- liftIO $ IO.hGetBuf handle ptr defaultChunkSize
+            when (count > 0) $ do
+                yield (PS fptr 0 count)
+                loop
+
+    loop
+
+    liftIO $ touchForeignPtr fptr
 
 -- | An alternative to 'sourceHandle'.
 -- Instead of taking a pre-opened 'IO.Handle', it takes an action that opens
diff --git a/Data/Conduit/Internal.hs b/Data/Conduit/Internal.hs
--- a/Data/Conduit/Internal.hs
+++ b/Data/Conduit/Internal.hs
@@ -805,8 +805,8 @@
 -- the @Sink@ uses @catchC@, the exception will /not/ be caught.
 --
 -- Due to this behavior (as well as lack of async exception handling), you
--- should not try to implement combinators such @onException@ in terms of this
--- primitive.
+-- should not try to implement combinators such as @onException@ in terms of this
+-- primitive function.
 --
 -- Note also that the exception handling will /not/ be applied to any
 -- finalizers generated by this conduit.
diff --git a/Data/Conduit/Lift.hs b/Data/Conduit/Lift.hs
--- a/Data/Conduit/Lift.hs
+++ b/Data/Conduit/Lift.hs
@@ -1,23 +1,11 @@
 {-# LANGUAGE RankNTypes #-}
-{- | Allow monad transformers to be run/eval/exec in a section of conduit
- rather then needing to run across the whole conduit.
-The circumvents many of the problems with breaking the monad transformer laws.
-Read more about when the monad transformer laws are broken:
-<https://github.com/snoyberg/conduit/wiki/Dealing-with-monad-transformers>
-
-This method has a considerable number of advantages over the other two 
-recommended methods.
-
-* Run the monad transformer outisde of the conduit
-* Use a mutable varible inside a readerT to retain side effects.
-
-This functionality has existed for awhile in the pipes ecosystem and my recent
-improvement to the Pipes.Lift module has allowed it to almost mechanically 
-translated for conduit.
-
--}
-
-
+-- | Allow monad transformers to be run/eval/exec in a section of conduit
+-- rather then needing to run across the whole conduit.  The circumvents many
+-- of the problems with breaking the monad transformer laws.  For more
+-- information, see the announcement blog post:
+-- <http://www.yesodweb.com/blog/2014/01/conduit-transformer-exception>
+--
+-- This module was added in conduit 1.0.11.
 module Data.Conduit.Lift (
     -- * ErrorT
     errorC,
diff --git a/conduit.cabal b/conduit.cabal
--- a/conduit.cabal
+++ b/conduit.cabal
@@ -1,5 +1,5 @@
 Name:                conduit
-Version:             1.0.11.1
+Version:             1.0.12
 Synopsis:            Streaming data processing library.
 Description:
     @conduit@ is a solution to the streaming data problem, allowing for production, transformation, and consumption of streams of data in constant memory. It is an alternative to lazy I\/O which guarantees deterministic resource handling, and fits in the same general solution space as @enumerator@\/@iteratee@ and @pipes@. For a tutorial, please visit <https://haskell.fpcomplete.com/user/snoyberg/library-documentation/conduit-overview>.