diff --git a/packages/backend/src/const.ts b/packages/backend/src/const.ts
index a238f4973a..8579f5d187 100644
--- a/packages/backend/src/const.ts
+++ b/packages/backend/src/const.ts
@@ -8,6 +8,11 @@ export const MAX_NOTE_TEXT_LENGTH = 3000;
 export const USER_ONLINE_THRESHOLD = 1000 * 60 * 10; // 10min
 export const USER_ACTIVE_THRESHOLD = 1000 * 60 * 60 * 24 * 3; // 3days
 
+export const REMOTE_USER_CACHE_TTL = 1000 * 60 * 60 * 3; // 3hours
+export const REMOTE_USER_MOVE_COOLDOWN = 1000 * 60 * 60 * 24 * 14; // 14days
+
+export const REMOTE_SERVER_CACHE_TTL = 1000 * 60 * 60 * 3; // 3hours
+
 //#region hard limits
 // If you change DB_* values, you must also change the DB schema.
 
diff --git a/packages/backend/src/core/FetchInstanceMetadataService.ts b/packages/backend/src/core/FetchInstanceMetadataService.ts
index fc4f335d54..d038646d0d 100644
--- a/packages/backend/src/core/FetchInstanceMetadataService.ts
+++ b/packages/backend/src/core/FetchInstanceMetadataService.ts
@@ -15,6 +15,7 @@ import { LoggerService } from '@/core/LoggerService.js';
 import { HttpRequestService } from '@/core/HttpRequestService.js';
 import { bindThis } from '@/decorators.js';
 import { FederatedInstanceService } from '@/core/FederatedInstanceService.js';
+import { REMOTE_SERVER_CACHE_TTL } from '@/const';
 import type { DOMWindow } from 'jsdom';
 
 type NodeInfo = {
@@ -73,7 +74,7 @@ export class FetchInstanceMetadataService {
 			if (!force) {
 				const _instance = await this.federatedInstanceService.fetch(host);
 				const now = Date.now();
-				if (_instance && _instance.infoUpdatedAt && (now - _instance.infoUpdatedAt.getTime() < 1000 * 60 * 60 * 3)) {
+				if (_instance && _instance.infoUpdatedAt && (now - _instance.infoUpdatedAt.getTime() < REMOTE_SERVER_CACHE_TTL)) {
 					throw new Error('Skip because updated recently');
 				}
 			}
diff --git a/packages/backend/src/core/activitypub/models/ApPersonService.ts b/packages/backend/src/core/activitypub/models/ApPersonService.ts
index 000d1d4144..97abfcbde8 100644
--- a/packages/backend/src/core/activitypub/models/ApPersonService.ts
+++ b/packages/backend/src/core/activitypub/models/ApPersonService.ts
@@ -40,6 +40,7 @@ import { DriveFileEntityService } from '@/core/entities/DriveFileEntityService.j
 import type { AccountMoveService } from '@/core/AccountMoveService.js';
 import { checkHttps } from '@/misc/check-https.js';
 import { isNotNull } from '@/misc/is-not-null.js';
+import { REMOTE_USER_CACHE_TTL, REMOTE_USER_MOVE_COOLDOWN } from '@/const.js';
 import { getApId, getApType, getOneApHrefNullable, isActor, isCollection, isCollectionOrOrderedCollection, isPropertyValue } from '../type.js';
 import { extractApHashtags } from './tag.js';
 import type { OnModuleInit } from '@nestjs/common';
@@ -255,7 +256,7 @@ export class ApPersonService implements OnModuleInit {
 
 		// ついでにリモートユーザーの情報が古かったら更新しておく
 		if (this.userEntityService.isRemoteUser(exist)) {
-			if (exist.lastFetchedAt == null || Date.now() - exist.lastFetchedAt.getTime() > 1000 * 60 * 60 * 3) {
+			if (exist.lastFetchedAt == null || Date.now() - exist.lastFetchedAt.getTime() > REMOTE_USER_CACHE_TTL) {
 				this.logger.debug('fetchPersonWithRenewal: renew', { uri, lastFetchedAt: exist.lastFetchedAt });
 				await this.updatePerson(exist.uri);
 				return await this.fetchPerson(uri);
@@ -619,7 +620,7 @@ export class ApPersonService implements OnModuleInit {
 			exist.movedAt == null ||
 			// 以前のmovingから14日以上経過した場合のみ移行処理を許可
 			// （Mastodonのクールダウン期間は30日だが若干緩めに設定しておく）
-			exist.movedAt.getTime() + 1000 * 60 * 60 * 24 * 14 < updated.movedAt.getTime()
+			exist.movedAt.getTime() + REMOTE_USER_MOVE_COOLDOWN < updated.movedAt.getTime()
 		)) {
 			this.logger.info(`Start to process Move of @${updated.username}@${updated.host} (${uri})`);
 			return this.processRemoteMove(updated, movePreventUris)