diff --git a/Annex/Import.hs b/Annex/Import.hs
index 712e125c5e..e1fc492e8e 100644
--- a/Annex/Import.hs
+++ b/Annex/Import.hs
@@ -25,9 +25,7 @@ import Git.Sha
 import Git.FilePath
 import qualified Git.Ref
 import qualified Git.Branch
-import qualified Git.DiffTree as DiffTree
 import qualified Annex
-import qualified Annex.Branch
 import Annex.Link
 import Annex.LockFile
 import Annex.Content
@@ -38,7 +36,6 @@ import Types.Key
 import Types.KeySource
 import Utility.Metered
 import Utility.DataUnits
-import Logs
 import Logs.Export
 import Logs.Location
 import qualified Database.Export as Export
@@ -223,7 +220,8 @@ downloadImport remote importtreeconfig importablecontents = do
 	cidmap <- liftIO $ newTVarIO M.empty
 	withExclusiveLock gitAnnexContentIdentifierLock $
 		bracket CIDDb.openDb CIDDb.closeDb $ \db -> do
-			updateContentIdentifierDbFromBranch db
+			CIDDb.needsUpdateFromLog db
+				>>= maybe noop (CIDDb.updateFromLog db)
 			go cidmap importablecontents db
 	-- TODO really support concurrency; avoid donwloading the same
 	-- ContentIdentifier twice.
@@ -295,32 +293,3 @@ importKey (ContentIdentifier cid) size = stubKey
 	, keyVariety = OtherKey "CID"
 	, keySize = Just size
 	}
-
-{- Updates the ContentIdentifier database with information from the
- - git-annex branch. This way, ContentIdentifiers that have been imported
- - in other clones of the repository will be known, and not unncessarily
- - downloaded again.
- -
- - The database should already be locked for write.
- -}
-updateContentIdentifierDbFromBranch :: CIDDb.ContentIdentifierHandle -> Annex ()
-updateContentIdentifierDbFromBranch db = do
-	oldtree <- liftIO $ CIDDb.getAnnexBranchTree db
-	inRepo (Git.Ref.tree Annex.Branch.fullname) >>= \case
-		Just currtree | currtree /= oldtree -> do
-			(l, cleanup) <- inRepo $
-				DiffTree.diffTreeRecursive oldtree currtree
-			mapM_ go l
-			void $ liftIO $ cleanup
-			liftIO $ do
-				CIDDb.recordAnnexBranchTree db t currtree
-				CIDDb.flushDbQueue db
-		_ -> return ()
-  where
-	go ti = case extLogFileKey remoteContentIdentifierExt (getTopFilePath (DiffTree.file ti)) of
-		Nothing -> return ()
-		Just k -> do
-			l <- CIDLog.getContentIdentifiers k
-			liftIO $ forM_ l $ \(u, cids) ->
-				forM_ cids $ \cid ->
-					CIDDb.recordContentIdentifier db u cid k
diff --git a/Database/ContentIdentifier.hs b/Database/ContentIdentifier.hs
index 0209fbfc7e..585e3dc8d1 100644
--- a/Database/ContentIdentifier.hs
+++ b/Database/ContentIdentifier.hs
@@ -24,6 +24,8 @@ module Database.ContentIdentifier (
 	getContentIdentifierKeys,
 	recordAnnexBranchTree,
 	getAnnexBranchTree,
+	needsUpdateFromLog,
+	updateFromLog,
 	ContentIdentifiersId,
 	AnnexBranchId,
 ) where
@@ -33,9 +35,15 @@ import qualified Database.Queue as H
 import Database.Init
 import Annex.Locations
 import Annex.Common hiding (delete)
+import qualified Annex.Branch
 import Types.Import
 import Git.Types
 import Git.Sha
+import Git.FilePath
+import qualified Git.Ref
+import qualified Git.DiffTree as DiffTree
+import Logs
+import qualified Logs.ContentIdentifier as Log
 
 import Database.Persist.Sql hiding (Key)
 import Database.Persist.TH
@@ -119,3 +127,32 @@ getAnnexBranchTree (ContentIdentifierHandle h) = H.queryDbQueue h $ do
         case l of
                 (s:[]) -> return $ fromSRef $ annexBranchTree $ entityVal s
                 _ -> return emptyTree
+
+{- Check if the git-annex branch has been updated and the database needs
+ - to be updated with any new content identifiers in it. -}
+needsUpdateFromLog :: ContentIdentifierHandle -> Annex (Maybe (Sha, Sha))
+needsUpdateFromLog db = do
+	oldtree <- liftIO $ getAnnexBranchTree db
+	inRepo (Git.Ref.tree Annex.Branch.fullname) >>= \case
+		Just currtree | currtree /= oldtree ->
+			return $ Just (oldtree, currtree)
+		_ -> return Nothing
+
+{- The database should be locked for write when calling this. -}
+updateFromLog :: ContentIdentifierHandle -> (Sha, Sha) -> Annex ()
+updateFromLog db (oldtree, currtree) = do
+	(l, cleanup) <- inRepo $
+		DiffTree.diffTreeRecursive oldtree currtree
+	mapM_ go l
+	void $ liftIO $ cleanup
+	liftIO $ do
+		recordAnnexBranchTree db currtree
+		flushDbQueue db
+  where
+	go ti = case extLogFileKey remoteContentIdentifierExt (getTopFilePath (DiffTree.file ti)) of
+		Nothing -> return ()
+		Just k -> do
+			l <- Log.getContentIdentifiers k
+			liftIO $ forM_ l $ \(u, cids) ->
+				forM_ cids $ \cid ->
+					recordContentIdentifier db u cid k