diff --git a/Database/MongoDB/Query.hs b/Database/MongoDB/Query.hs
index 1d6827f..f8201f0 100644
--- a/Database/MongoDB/Query.hs
+++ b/Database/MongoDB/Query.hs
@@ -47,7 +47,7 @@ import Data.Int (Int32)
 import Data.Maybe (listToMaybe, catMaybes)
 import Data.Word (Word32)
 
-import Control.Concurrent.MVar.Lifted (MVar, newMVar, addMVarFinalizer,
+import Control.Concurrent.MVar.Lifted (MVar, newMVar, mkWeakMVar,
                                        readMVar, modifyMVar)
 import Control.Monad.Base (MonadBase(liftBase))
 import Control.Monad.Error (ErrorT, Error(..), MonadError, runErrorT,
@@ -509,7 +509,7 @@ newCursor :: (MonadIO m, MonadBaseControl IO m) => Database -> Collection -> Bat
 newCursor db col batchSize dBatch = do
 	var <- newMVar dBatch
 	let cursor = Cursor (db <.> col) batchSize var
-	addMVarFinalizer var (closeCursor cursor)
+	mkWeakMVar var (closeCursor cursor)
 	return cursor
 
 nextBatch :: (MonadIO m, MonadBaseControl IO m) => Cursor -> Action m [Document]
diff --git a/System/IO/Pipeline.hs b/System/IO/Pipeline.hs
index e88c40c..97b25a8 100644
--- a/System/IO/Pipeline.hs
+++ b/System/IO/Pipeline.hs
@@ -20,7 +20,7 @@ import GHC.Conc (ThreadStatus(..), threadStatus)
 
 import Control.Monad.Trans (liftIO)
 import Control.Concurrent.MVar.Lifted (MVar, newEmptyMVar, newMVar, withMVar,
-                                       putMVar, readMVar, addMVarFinalizer)
+                                       putMVar, readMVar, mkWeakMVar)
 import Control.Monad.Error (ErrorT(ErrorT), runErrorT)
 
 onException :: (Monad m) => ErrorT e m a -> m () -> ErrorT e m a
@@ -58,7 +58,7 @@ newPipeline stream = do
 	rec
 		let pipe = Pipeline{..}
 		listenThread <- forkIO (listen pipe)
-	addMVarFinalizer vStream $ do
+	mkWeakMVar vStream $ do
 		killThread listenThread
 		closeStream stream
 	return pipe