diff --git a/builtin/commit-graph.c b/builtin/commit-graph.c
index 8196fdbe9c..537fdfd0f0 100644
--- a/builtin/commit-graph.c
+++ b/builtin/commit-graph.c
@@ -62,8 +62,10 @@ static int graph_verify(int argc, const char **argv)
 
 	graph_name = get_commit_graph_filename(opts.obj_dir);
 	open_ok = open_commit_graph(graph_name, &fd, &st);
-	if (!open_ok)
+	if (!open_ok && errno == ENOENT)
 		return 0;
+	if (!open_ok)
+		die_errno(_("Could not open commit-graph '%s'"), graph_name);
 	graph = load_commit_graph_one_fd_st(fd, &st);
 	FREE_AND_NULL(graph_name);
 
diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
index 0d012f55e5..4601732b99 100755
--- a/t/t5318-commit-graph.sh
+++ b/t/t5318-commit-graph.sh
@@ -400,6 +400,12 @@ corrupt_graph_and_verify() {
 
 }
 
+test_expect_success POSIXPERM,SANITY 'detect permission problem' '
+	corrupt_graph_setup &&
+	chmod 000 $objdir/info/commit-graph &&
+	corrupt_graph_verify "Could not open"
+'
+
 test_expect_success 'detect too small' '
 	corrupt_graph_setup &&
 	echo "a small graph" >$objdir/info/commit-graph &&