diff --git a/CHANGELOG b/CHANGELOG
index 9c5ec5a91b..6f14915886 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -9,6 +9,8 @@ git-annex (10.20240832) UNRELEASED; urgency=medium
   * sim: New command, can be used to simulate networks of repositories
     and see how preferred content and other configuration makes file
     content flow through it.
+  * Fix bug that prevented anything being stored in an empty
+    repository whose preferred content expression uses sizebalanced.
 
  -- Joey Hess <id@joeyh.name>  Tue, 03 Sep 2024 12:38:42 -0400
 
diff --git a/Limit.hs b/Limit.hs
index 4ef4005abe..2c7ce3c22e 100644
--- a/Limit.hs
+++ b/Limit.hs
@@ -736,8 +736,8 @@ filterCandidatesFullySizeBalanced
 filterCandidatesFullySizeBalanced maxsizes sizemap n key candidates = do
 	currentlocs <- S.fromList <$> loggedLocations key
  	let keysize = fromMaybe 0 (fromKey keySize key)
-	let go u = case (M.lookup u maxsizes, M.lookup u sizemap, u `S.member` currentlocs) of
-		(Just maxsize, Just reposize, inrepo)
+	let go u = case (M.lookup u maxsizes, fromMaybe (RepoSize 0) (M.lookup u sizemap), u `S.member` currentlocs) of
+		(Just maxsize, reposize, inrepo)
 			| repoHasSpace keysize inrepo reposize maxsize ->
 				proportionfree keysize inrepo u reposize maxsize
 			| otherwise -> Nothing
diff --git a/doc/bugs/sizebalanced_preferred_content_empty_repo_stays_empty.mdwn b/doc/bugs/sizebalanced_preferred_content_empty_repo_stays_empty.mdwn
new file mode 100644
index 0000000000..afbdaf8296
--- /dev/null
+++ b/doc/bugs/sizebalanced_preferred_content_empty_repo_stays_empty.mdwn
@@ -0,0 +1,9 @@
+When using sizebalanced preferred content, a `git-annex copy --auto` to a
+repository that is currently empty will not fill it.
+
+It seems that getLiveRepoSizes returns a map that does not contain the
+repo's UUID, and filterCandidatesFullySizeBalanced filters out repos that
+are not in the map.
+--[[Joey]]
+
+> [[fixed|done]] --[[Joey]]