diff --git a/Annex/Locations.hs b/Annex/Locations.hs
index 6cfe0469fc..725415c23a 100644
--- a/Annex/Locations.hs
+++ b/Annex/Locations.hs
@@ -375,7 +375,7 @@ gitAnnexExportExcludeLog u r = gitAnnexDir r </> "export.ex" </> fromUUID u
  - need to be rebuilt with a new name.)
  -}
 gitAnnexContentIdentifierDbDir :: Git.Repo -> FilePath
-gitAnnexContentIdentifierDbDir r = gitAnnexDir r </> "cids"
+gitAnnexContentIdentifierDbDir r = gitAnnexDir r </> "cidsdb"
 
 {- Lock file for writing to the content id database. -}
 gitAnnexContentIdentifierLock :: Git.Repo -> FilePath
diff --git a/Upgrade/V7.hs b/Upgrade/V7.hs
index 0d06614b26..a3199f57c4 100644
--- a/Upgrade/V7.hs
+++ b/Upgrade/V7.hs
@@ -13,6 +13,7 @@ import Annex.Common
 import Annex.CatFile
 import qualified Database.Keys
 import qualified Database.Keys.SQL
+import qualified Database.ContentIdentifier
 import qualified Git.LsFiles as LsFiles
 import qualified Git
 import Git.FilePath
@@ -23,10 +24,17 @@ upgrade automatic = do
 		showAction "v7 to v8"
 	
 	populateKeysDb
+
 	-- The fsck databases are not transitioned here; any running
 	-- incremental fsck can continue to write to the old database.
 	-- The next time an incremental fsck is started, it will delete the
 	-- old database, and just re-fsck the files.
+	
+	-- The old content identifier database is deleted here, but the
+	-- new database is not populated. It will be automatically
+	-- populated from the git-annex branch the next time it is used.
+	removeOldDb gitAnnexContentIdentifierDbDirOld
+	liftIO . nukeFile =<< fromRepo gitAnnexContentIdentifierLockOld
 
 	removeOldDb gitAnnexKeysDbOld
 	liftIO . nukeFile =<< fromRepo gitAnnexKeysDbIndexCacheOld
@@ -43,6 +51,12 @@ gitAnnexKeysDbLockOld r = gitAnnexKeysDbOld r ++ ".lck"
 gitAnnexKeysDbIndexCacheOld :: Git.Repo -> FilePath
 gitAnnexKeysDbIndexCacheOld r = gitAnnexKeysDbOld r ++ ".cache"
 
+gitAnnexContentIdentifierDbDirOld :: Git.Repo -> FilePath
+gitAnnexContentIdentifierDbDirOld r = gitAnnexDir r </> "cids"
+
+gitAnnexContentIdentifierLockOld :: Git.Repo -> FilePath
+gitAnnexContentIdentifierLockOld r = gitAnnexContentIdentifierDbDirOld r ++ ".lck"
+
 removeOldDb :: (Git.Repo -> FilePath) -> Annex ()
 removeOldDb getdb = do
 	db <- fromRepo getdb
@@ -91,3 +105,4 @@ populateKeysDb = do
 						Database.Keys.SQL.addInodeCaches k [ic] h
 	liftIO $ void cleanup
 	Database.Keys.closeDb
+
diff --git a/doc/todo/sqlite_database_improvements.mdwn b/doc/todo/sqlite_database_improvements.mdwn
index 17997d6d43..acc12ebf99 100644
--- a/doc/todo/sqlite_database_improvements.mdwn
+++ b/doc/todo/sqlite_database_improvements.mdwn
@@ -98,8 +98,11 @@ remaining todo:
 >   (done)
 
 > * ContentIdentifier (IKey)  
->   rebuild with updateFromLog, would need to diff from empty tree to
+>   rebuild with updateFromLog, will need to diff from empty tree to
 >   current git-annex branch, may be expensive to do!
+
+    (done; will be done automatically by the first command that needs to
+    use the db)
 > 
 > * Export (IKey, SFilePath)  
 >   difficult to rebuild, what if in the middle of an interrupted