diff --git a/commit-graph.c b/commit-graph.c
index 98bbbbfc32..1a16d49bcb 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -1602,8 +1602,8 @@ static void split_graph_merge_strategy(struct write_commit_graph_context *ctx)
 		free(old_graph_name);
 	}
 
-	ALLOC_ARRAY(ctx->commit_graph_filenames_after, ctx->num_commit_graphs_after);
-	ALLOC_ARRAY(ctx->commit_graph_hash_after, ctx->num_commit_graphs_after);
+	CALLOC_ARRAY(ctx->commit_graph_filenames_after, ctx->num_commit_graphs_after);
+	CALLOC_ARRAY(ctx->commit_graph_hash_after, ctx->num_commit_graphs_after);
 
 	for (i = 0; i < ctx->num_commit_graphs_after &&
 		    i < ctx->num_commit_graphs_before; i++)
diff --git a/t/t5324-split-commit-graph.sh b/t/t5324-split-commit-graph.sh
index 87a9148fbe..1024f62f49 100755
--- a/t/t5324-split-commit-graph.sh
+++ b/t/t5324-split-commit-graph.sh
@@ -374,4 +374,17 @@ test_expect_success '--split=replace replaces the chain' '
 	graph_read_expect 2
 '
 
+test_expect_success ULIMIT_FILE_DESCRIPTORS 'handles file descriptor exhaustion' '
+	git init ulimit &&
+	(
+		cd ulimit &&
+		for i in $(test_seq 64)
+		do
+			test_commit $i &&
+			test_might_fail run_with_limited_open_files git commit-graph write \
+				--split=no-merge --reachable || return 1
+		done
+	)
+'
+
 test_done