diff --git a/Annex/Import.hs b/Annex/Import.hs
index d653208ea3..252922d2ae 100644
--- a/Annex/Import.hs
+++ b/Annex/Import.hs
@@ -233,12 +233,14 @@ downloadImport remote importtreeconfig importablecontents = do
 		(k:_) -> return $ Just (loc, k)
 		[] -> checkDiskSpaceToGet tmpkey Nothing $
 			withTmp tmpkey $ \tmpfile ->
-				Remote.retrieveExportWithContentIdentifier ia loc cid tmpfile (ingestkey loc tmpfile) p >>= \case
-					Just k -> do
-						recordcidkey cidmap db cid k
-						logStatus k InfoPresent
-						logChange k (Remote.uuid remote) InfoPresent
-						return $ Just (loc, k)
+				Remote.retrieveExportWithContentIdentifier ia loc cid tmpfile (mkkey loc tmpfile) p >>= \case
+					Just k -> tryNonAsync (moveAnnex k tmpfile) >>= \case
+						Right True -> do
+							recordcidkey cidmap db cid k
+							logStatus k InfoPresent
+							logChange k (Remote.uuid remote) InfoPresent
+							return $ Just (loc, k)
+						_ -> return Nothing
 					Nothing -> return Nothing
 	  where
 		-- TODO progress bar
@@ -246,7 +248,7 @@ downloadImport remote importtreeconfig importablecontents = do
 		ia = Remote.importActions remote
 		tmpkey = importKey cid sz
 	
-	ingestkey loc tmpfile = do
+	mkkey loc tmpfile = do
 		f <- fromRepo $ fromTopFilePath $ locworktreefilename loc
 		backend <- chooseBackend f
 		let ks = KeySource
@@ -254,12 +256,7 @@ downloadImport remote importtreeconfig importablecontents = do
 			, contentLocation = tmpfile
 			, inodeCache = Nothing
 			}
-		genKey ks backend >>= \case
-			Nothing -> return Nothing
-			Just (k, _) ->
-				tryNonAsync (moveAnnex k tmpfile) >>= \case
-					Right True -> return (Just k)
-					_ -> return Nothing
+		fmap fst <$> genKey ks backend
 
 	locworktreefilename loc = asTopFilePath $ case importtreeconfig of
 		ImportTree -> fromImportLocation loc
diff --git a/Remote/Directory.hs b/Remote/Directory.hs
index bddd97fbd0..01b8eb357a 100644
--- a/Remote/Directory.hs
+++ b/Remote/Directory.hs
@@ -33,6 +33,7 @@ import Annex.Content
 import Annex.UUID
 import Utility.Metered
 import Utility.Tmp
+import Utility.InodeCache
 
 remote :: RemoteType
 remote = RemoteType
@@ -300,22 +301,90 @@ listImportableContentsM :: FilePath -> Annex (Maybe (ImportableContents (Content
 listImportableContentsM dir = catchMaybeIO $ liftIO $ do
 	l <- dirContentsRecursive dir
 	l' <- mapM go l
-	return $ ImportableContents l' []
+	return $ ImportableContents (catMaybes l') []
   where
 	go f = do
-		sz <- getFileSize f
-		loc <- mkImportLocation <$> relPathDirToFile dir f
-		-- TODO use inode, size etc
-		let cid = ContentIdentifier $ encodeBS f
-		return (loc, (cid, sz))
+		st <- getFileStatus f
+		mkContentIdentifier f st >>= \case
+			Nothing -> return Nothing
+			Just cid -> do
+				relf <- relPathDirToFile dir f
+				sz <- getFileSize' f st
+				return $ Just (mkImportLocation relf, (cid, sz))
+
+-- Make a ContentIdentifier that contains an InodeCache.
+--
+-- The InodeCache is generated without checking a sentinal file.
+-- So in a case when a remount etc causes all the inodes to change,
+-- files may appear to be modified when they are not, which will only
+-- result in extra work to re-import them.
+--
+-- If the file is not a regular file, this will return Nothing.
+mkContentIdentifier :: FilePath -> FileStatus -> IO (Maybe ContentIdentifier)
+mkContentIdentifier f st =
+	fmap (ContentIdentifier . encodeBS . showInodeCache)
+		<$> toInodeCache noTSDelta f st
 
 retrieveExportWithContentIdentifierM :: FilePath -> ExportLocation -> ContentIdentifier -> FilePath -> Annex (Maybe Key) -> MeterUpdate -> Annex (Maybe Key)
-retrieveExportWithContentIdentifierM dir loc cid dest mkkey p = catchDefaultIO Nothing $ do
-	-- TODO check the ContentIdentifier is valid (avoiding all races)
-	let f = dir </> fromExportLocation loc
-	h <- liftIO $ openBinaryFile f ReadMode
-	liftIO $ hGetContentsMetered h p >>= L.writeFile dest
-	mkkey
+retrieveExportWithContentIdentifierM dir loc cid dest mkkey p = 
+	catchDefaultIO Nothing $ precheck $ docopy postcheck
+  where
+	f = dir </> fromExportLocation loc
+
+	docopy cont = do
+#ifndef mingw32_HOST_OS
+		-- Need a duplicate fd for the post check, since
+		-- hGetContentsMetered closes its handle.
+		fd <- liftIO $ openFd f ReadOnly Nothing defaultFileFlags
+		dupfd <- liftIO $ dup fd
+		h <- liftIO $ fdToHandle fd
+#else
+		h <- liftIO $ openBinaryFile f ReadMode
+#endif
+		liftIO $ hGetContentsMetered h p >>= L.writeFile dest
+		k <- mkkey
+#ifndef mingw32_HOST_OS
+		cont dupfd (return k)
+#else
+		cont (return k)
+#endif
+	
+	-- Check before copy, to avoid expensive copy of wrong file
+	-- content.
+	precheck cont = comparecid cont
+		=<< liftIO . mkContentIdentifier f
+		=<< liftIO (getFileStatus f)
+
+	-- Check after copy, in case the file was changed while it was
+	-- being copied.
+	--
+	-- When possible (not on Windows), check the same handle
+	-- Check the same handle that the file was copied from.
+	-- Avoids some race cases where the file is modified while
+	-- it's copied but then gets restored to the original content
+	-- afterwards.
+	--
+	-- This does not guard against every possible race, but neither
+	-- can InodeCaches detect every possible modification to a file.
+	-- It's probably as good or better than git's handling of similar
+	-- situations with files being modified while it's updating the
+	-- working tree for a merge.
+#ifndef mingw32_HOST_OS
+	postcheck fd cont = do
+#else
+	postcheck cont = do
+#endif
+		currcid <- liftIO $ mkContentIdentifier f
+#ifndef mingw32_HOST_OS
+			=<< getFdStatus fd
+#else
+			=<< getFileStatus f
+#endif
+		comparecid cont currcid
+	
+	comparecid cont currcid
+		| currcid == Just cid = cont
+		| otherwise = return Nothing
 
 storeExportWithContentIdentifierM :: FilePath -> FilePath -> Key -> ExportLocation -> [ContentIdentifier] -> MeterUpdate -> Annex (Maybe ContentIdentifier)
 storeExportWithContentIdentifierM dir = error "TODO"
diff --git a/doc/todo/import_tree.mdwn b/doc/todo/import_tree.mdwn
index 3e928eaa68..07a9132c7b 100644
--- a/doc/todo/import_tree.mdwn
+++ b/doc/todo/import_tree.mdwn
@@ -10,9 +10,6 @@ this.
 
 ## implementation notes
 
-* directory special remote import is prototype, does not notice modified
-  files, not race safe
-
 * Need to support annex-tracking-branch configuration, which documentation
   says makes git-annex sync and assistant do imports.