diff --git a/Annex/Init.hs b/Annex/Init.hs
index b9d41b0eaf..b05a7d6871 100644
--- a/Annex/Init.hs
+++ b/Annex/Init.hs
@@ -230,9 +230,10 @@ probeLockSupport = withEventuallyCleanedOtherTmp $ \tmp -> do
   where
 	go f mode = do
 		nukeFile f
-		let locktest = mask $ const $
-			Posix.lockExclusive (Just mode) f
-				>>= Posix.dropLock
+		let locktest = bracket
+			(Posix.lockExclusive (Just mode) f)
+			Posix.dropLock
+			(const noop)
 		ok <- isRight <$> tryNonAsync locktest
 		nukeFile f
 		return ok
diff --git a/Annex/LockPool/PosixOrPid.hs b/Annex/LockPool/PosixOrPid.hs
index e078424390..6230544117 100644
--- a/Annex/LockPool/PosixOrPid.hs
+++ b/Annex/LockPool/PosixOrPid.hs
@@ -94,5 +94,4 @@ tryPidLock m f posixlock = debugLocks $ liftIO . go =<< pidLockFile
 -- avoid complicating any code that might expect to be able to see that
 -- lock file. But, it's not locked.
 dummyPosixLock :: Maybe FileMode -> LockFile -> IO ()
-dummyPosixLock m f = mask $ const $
-	closeFd =<< openLockFile ReadLock m f
+dummyPosixLock m f = bracket (openLockFile ReadLock m f) closeFd (const noop)
diff --git a/Remote/Helper/Ssh.hs b/Remote/Helper/Ssh.hs
index be3a9b7f3e..d44785897b 100644
--- a/Remote/Helper/Ssh.hs
+++ b/Remote/Helper/Ssh.hs
@@ -200,7 +200,7 @@ closeP2PSshConnection :: P2PSshConnection -> IO (P2PSshConnection, Maybe ExitCod
 closeP2PSshConnection P2P.ClosedConnection = return (P2P.ClosedConnection, Nothing)
 closeP2PSshConnection (P2P.OpenConnection (_st, conn, pid, stderrhandlerst)) =
 	-- mask async exceptions, avoid cleanup being interrupted
-	mask $ const $ do
+	uninterruptibleMask_ $ do
 		P2P.closeConnection conn
 		atomically $ writeTVar stderrhandlerst EndStderrHandler
 		exitcode <- waitForProcess pid
diff --git a/Utility/LockFile/Posix.hs b/Utility/LockFile/Posix.hs
index 03c9e96c14..011d8f953b 100644
--- a/Utility/LockFile/Posix.hs
+++ b/Utility/LockFile/Posix.hs
@@ -58,7 +58,7 @@ lock lockreq mode lockfile = do
 
 -- Tries to take an lock, but does not block.
 tryLock :: LockRequest -> Maybe FileMode -> LockFile -> IO (Maybe LockHandle)
-tryLock lockreq mode lockfile = mask $ const $ do
+tryLock lockreq mode lockfile = uninterruptibleMask_ $ do
 	l <- openLockFile lockreq mode lockfile
 	v <- tryIO $ setLock l (lockreq, AbsoluteSeek, 0, 0)
 	case v of