diff --git a/packages/backend/src/remote/activitypub/kernel/index.ts b/packages/backend/src/remote/activitypub/kernel/index.ts
index 1bbb1401c..ab6ef0ef1 100644
--- a/packages/backend/src/remote/activitypub/kernel/index.ts
+++ b/packages/backend/src/remote/activitypub/kernel/index.ts
@@ -1,10 +1,9 @@
 import { IRemoteUser } from '@/models/entities/user.js';
-import { toArray } from '@/prelude/array.js';
 import { Resolver } from '@/remote/activitypub/resolver.js';
 import { extractPunyHost } from '@/misc/convert-host.js';
 import { shouldBlockInstance } from '@/misc/should-block-instance.js';
 import { apLogger } from '../logger.js';
-import { IObject, isCreate, isDelete, isUpdate, isRead, isFollow, isAccept, isReject, isAdd, isRemove, isAnnounce, isLike, isUndo, isBlock, isCollectionOrOrderedCollection, isCollection, isFlag, isMove, getApId } from '../type.js';
+import { IObject, isCreate, isDelete, isUpdate, isRead, isFollow, isAccept, isReject, isAdd, isRemove, isAnnounce, isLike, isUndo, isBlock, isFlag, isMove, getApId } from '../type.js';
 import create from './create/index.js';
 import performDeleteActivity from './delete/index.js';
 import performUpdateActivity from './update/index.js';
@@ -22,23 +21,6 @@ import flag from './flag/index.js';
 import { move } from './move/index.js';
 
 export async function performActivity(actor: IRemoteUser, activity: IObject, resolver: Resolver): Promise<void> {
-	if (isCollectionOrOrderedCollection(activity)) {
-		for (const item of toArray(isCollection(activity) ? activity.items : activity.orderedItems)) {
-			const act = await resolver.resolve(item);
-			try {
-				await performOneActivity(actor, act, resolver);
-			} catch (err) {
-				if (err instanceof Error || typeof err === 'string') {
-					apLogger.error(err);
-				}
-			}
-		}
-	} else {
-		await performOneActivity(actor, activity, resolver);
-	}
-}
-
-async function performOneActivity(actor: IRemoteUser, activity: IObject, resolver: Resolver): Promise<void> {
 	if (actor.isSuspended) return;
 
 	if (typeof activity.id !== 'undefined') {