diff --git a/packages/backend/src/misc/collapsed-queue.ts b/packages/backend/src/misc/collapsed-queue.ts
index dee6df32bd2e..5bc20a78ae29 100644
--- a/packages/backend/src/misc/collapsed-queue.ts
+++ b/packages/backend/src/misc/collapsed-queue.ts
@@ -8,6 +8,7 @@ type Job<V> = {
 	timer: NodeJS.Timeout;
 };
 
+// TODO: redis使えるようにする
 export class CollapsedQueue<K, V> {
 	private jobs: Map<K, Job<V>> = new Map();