diff --git a/Annex/Branch.hs b/Annex/Branch.hs
index d75b8f249b..8afe6f9912 100644
--- a/Annex/Branch.hs
+++ b/Annex/Branch.hs
@@ -410,15 +410,21 @@ getRef ref file = withIndex $ catFile ref file
 change :: Journalable content => RegardingUUID -> RawFilePath -> (L.ByteString -> content) -> Annex ()
 change ru file f = lockJournal $ \jl -> f <$> getToChange ru file >>= set jl ru file
 
-{- Applies a function which can modify the content of a file, or not. -}
-maybeChange :: Journalable content => RegardingUUID -> RawFilePath -> (L.ByteString -> Maybe content) -> Annex ()
+{- Applies a function which can modify the content of a file, or not.
+ -
+ - Returns True when the file was modified. -}
+maybeChange :: Journalable content => RegardingUUID -> RawFilePath -> (L.ByteString -> Maybe content) -> Annex Bool
 maybeChange ru file f = lockJournal $ \jl -> do
 	v <- getToChange ru file
 	case f v of
 		Just jv ->
 			let b = journalableByteString jv
-			in when (v /= b) $ set jl ru file b
-		_ -> noop
+			in if v /= b
+				then do
+					set jl ru file b
+					return True
+				else return False
+		_ -> return False
 
 data ChangeOrAppend t = Change t | Append t
 
diff --git a/Annex/RepoSize.hs b/Annex/RepoSize.hs
index dac089a962..d9fa13794d 100644
--- a/Annex/RepoSize.hs
+++ b/Annex/RepoSize.hs
@@ -12,6 +12,7 @@ module Annex.RepoSize (
 ) where
 
 import Annex.Common
+import Annex.RepoSize.LiveUpdate
 import qualified Annex
 import Annex.Branch (UnmergedBranches(..), getBranch)
 import Types.RepoSize
@@ -86,17 +87,3 @@ journalledRepoSizes startmap branchsha =
 	accumsizes k (newlocs, removedlocs) m = return $
 		let m' = foldl' (flip $ M.alter $ addKeyRepoSize k) m newlocs
 		in foldl' (flip $ M.alter $ removeKeyRepoSize k) m' removedlocs
-
-addKeyRepoSize :: Key -> Maybe RepoSize -> Maybe RepoSize
-addKeyRepoSize k mrs = case mrs of
-	Just (RepoSize sz) -> Just $ RepoSize $ sz + ksz
-	Nothing -> Just $ RepoSize ksz
-  where
-	ksz = fromMaybe 0 $ fromKey keySize k
-
-removeKeyRepoSize :: Key -> Maybe RepoSize -> Maybe RepoSize
-removeKeyRepoSize k mrs = case mrs of
-	Just (RepoSize sz) -> Just $ RepoSize $ sz - ksz
-	Nothing -> Nothing
-  where
-	ksz = fromMaybe 0 $ fromKey keySize k
diff --git a/Annex/RepoSize/LiveUpdate.hs b/Annex/RepoSize/LiveUpdate.hs
new file mode 100644
index 0000000000..d9a7d6c35c
--- /dev/null
+++ b/Annex/RepoSize/LiveUpdate.hs
@@ -0,0 +1,46 @@
+{- git-annex repo sizes, live updates
+ -
+ - Copyright 2024 Joey Hess <id@joeyh.name>
+ -
+ - Licensed under the GNU AGPL version 3 or higher.
+ -}
+
+{-# LANGUAGE BangPatterns #-}
+
+module Annex.RepoSize.LiveUpdate where
+
+import Annex.Common
+import qualified Annex
+import Types.RepoSize
+import Logs.Presence.Pure
+
+import qualified Data.Map.Strict as M
+
+updateRepoSize :: UUID -> Key -> LogStatus -> Annex ()
+updateRepoSize u k s = Annex.getState Annex.reposizes >>= \case
+	Nothing -> noop
+	Just sizemap -> do
+		let !sizemap' = M.adjust 
+			(fromMaybe (RepoSize 0) . f k . Just)
+			u sizemap
+		Annex.changeState $ \st -> st
+			{ Annex.reposizes = Just sizemap' }
+  where
+	f = case s of
+		InfoPresent -> addKeyRepoSize
+		InfoMissing -> removeKeyRepoSize
+		InfoDead -> removeKeyRepoSize
+
+addKeyRepoSize :: Key -> Maybe RepoSize -> Maybe RepoSize
+addKeyRepoSize k mrs = case mrs of
+	Just (RepoSize sz) -> Just $ RepoSize $ sz + ksz
+	Nothing -> Just $ RepoSize ksz
+  where
+	ksz = fromMaybe 0 $ fromKey keySize k
+
+removeKeyRepoSize :: Key -> Maybe RepoSize -> Maybe RepoSize
+removeKeyRepoSize k mrs = case mrs of
+	Just (RepoSize sz) -> Just $ RepoSize $ sz - ksz
+	Nothing -> Nothing
+  where
+	ksz = fromMaybe 0 $ fromKey keySize k
diff --git a/Logs/ContentIdentifier.hs b/Logs/ContentIdentifier.hs
index 6448693ae7..bf8fef5b2e 100644
--- a/Logs/ContentIdentifier.hs
+++ b/Logs/ContentIdentifier.hs
@@ -32,7 +32,7 @@ recordContentIdentifier :: RemoteStateHandle -> ContentIdentifier -> Key -> Anne
 recordContentIdentifier (RemoteStateHandle u) cid k = do
 	c <- currentVectorClock
 	config <- Annex.getGitConfig
-	Annex.Branch.maybeChange
+	void $ Annex.Branch.maybeChange
 		(Annex.Branch.RegardingUUID [u])
 		(remoteContentIdentifierLogFile config k)
 		(addcid c . parseLog)
diff --git a/Logs/Location.hs b/Logs/Location.hs
index 73c1c5fe48..78ad36d60a 100644
--- a/Logs/Location.hs
+++ b/Logs/Location.hs
@@ -40,6 +40,7 @@ module Logs.Location (
 import Annex.Common
 import qualified Annex.Branch
 import Annex.Branch (FileContents)
+import Annex.RepoSize.LiveUpdate
 import Logs
 import Logs.Presence
 import Types.Cluster
@@ -81,11 +82,13 @@ logChange key u@(UUID _) s
 	| isClusterUUID u = noop
 	| otherwise = do
 		config <- Annex.getGitConfig
-		maybeAddLog
+		changed <- maybeAddLog
 			(Annex.Branch.RegardingUUID [u])
 			(locationLogFile config key)
 			s
 			(LogInfo (fromUUID u))
+		when changed $
+			updateRepoSize u key s
 logChange _ NoUUID _ = noop
 
 {- Returns a list of repository UUIDs that, according to the log, have
@@ -162,14 +165,15 @@ setDead key = do
 	ls <- compactLog <$> readLog logfile
 	mapM_ (go logfile) (filter (\l -> status l == InfoMissing) ls)
   where
-	go logfile l = 
+	go logfile l = do
 		let u = toUUID (fromLogInfo (info l))
 		    c = case date l of
 			VectorClock v -> CandidateVectorClock $
 				v + realToFrac (picosecondsToDiffTime 1)
 			Unknown -> CandidateVectorClock 0
-		in addLog' (Annex.Branch.RegardingUUID [u]) logfile InfoDead
+		addLog' (Annex.Branch.RegardingUUID [u]) logfile InfoDead
 			(info l) c
+		updateRepoSize u key InfoDead
 
 data Unchecked a = Unchecked (Annex (Maybe a))
 
diff --git a/Logs/Presence.hs b/Logs/Presence.hs
index 5c8dcdb343..6763e4676a 100644
--- a/Logs/Presence.hs
+++ b/Logs/Presence.hs
@@ -49,8 +49,10 @@ addLog' ru file logstatus loginfo c =
 {- When a LogLine already exists with the same status and info, but an
  - older timestamp, that LogLine is preserved, rather than updating the log
  - with a newer timestamp.
+ -
+ - Returns True when the log was changed.
  -}
-maybeAddLog :: Annex.Branch.RegardingUUID -> RawFilePath -> LogStatus -> LogInfo -> Annex ()
+maybeAddLog :: Annex.Branch.RegardingUUID -> RawFilePath -> LogStatus -> LogInfo -> Annex Bool
 maybeAddLog ru file logstatus loginfo = do
 	c <- currentVectorClock
 	Annex.Branch.maybeChange ru file $ \b ->
diff --git a/doc/todo/git-annex_proxies.mdwn b/doc/todo/git-annex_proxies.mdwn
index 89edd2bb71..b60822aee5 100644
--- a/doc/todo/git-annex_proxies.mdwn
+++ b/doc/todo/git-annex_proxies.mdwn
@@ -32,11 +32,6 @@ Planned schedule of work:
 
 * Implement [[track_free_space_in_repos_via_git-annex_branch]]:
 
-  * Update Annex.reposizes in Logs.Location.logChange,
-    when it makes a change and when Annex.reposizes has a size
-    for the UUID. So Annex.reposizes is kept up-to-date
-    for each transfer and drop.
-
   * When calling journalledRepoSizes make sure that the current
     process is prevented from making changes to the journal in another
     thread. Probably lock the journal? (No need to worry about changes made
diff --git a/git-annex.cabal b/git-annex.cabal
index b54a55c7a6..ce5aa132da 100644
--- a/git-annex.cabal
+++ b/git-annex.cabal
@@ -575,6 +575,7 @@ Executable git-annex
     Annex.ReplaceFile
     Annex.RemoteTrackingBranch
     Annex.RepoSize
+    Annex.RepoSize.LiveUpdate
     Annex.SafeDropProof
     Annex.SpecialRemote
     Annex.SpecialRemote.Config