diff --git a/read-cache.c b/read-cache.c
index 3e0e7d4183..68ed65035b 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -2268,8 +2268,11 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
 	istate->timestamp.nsec = 0;
 	fd = open(path, O_RDONLY);
 	if (fd < 0) {
-		if (!must_exist && errno == ENOENT)
+		if (!must_exist && errno == ENOENT) {
+			if (!istate->repo)
+				istate->repo = the_repository;
 			return 0;
+		}
 		die_errno(_("%s: index file open failed"), path);
 	}
 
diff --git a/t/t7063-status-untracked-cache.sh b/t/t7063-status-untracked-cache.sh
index 9936cc329e..c1f0d95036 100755
--- a/t/t7063-status-untracked-cache.sh
+++ b/t/t7063-status-untracked-cache.sh
@@ -985,4 +985,9 @@ test_expect_success '"status" after file replacement should be clean with UC=fal
 	status_is_clean
 '
 
+test_expect_success 'empty repo (no index) and core.untrackedCache' '
+	git init emptyrepo &&
+	git -C emptyrepo -c core.untrackedCache=true write-tree
+'
+
 test_done