diff --git a/packages/backend/src/core/FederatedInstanceService.ts b/packages/backend/src/core/FederatedInstanceService.ts
index e31d802e8c..662c7f7f2d 100644
--- a/packages/backend/src/core/FederatedInstanceService.ts
+++ b/packages/backend/src/core/FederatedInstanceService.ts
@@ -5,15 +5,13 @@
 
 import { Inject, Injectable, OnApplicationShutdown } from '@nestjs/common';
 import * as Redis from 'ioredis';
-import { DataSource, QueryFailedError } from 'typeorm';
 import type { InstancesRepository } from '@/models/_.js';
-import { MiInstance } from '@/models/Instance.js';
+import type { MiInstance } from '@/models/Instance.js';
 import { MemoryKVCache, RedisKVCache } from '@/misc/cache.js';
 import { IdService } from '@/core/IdService.js';
 import { DI } from '@/di-symbols.js';
 import { UtilityService } from '@/core/UtilityService.js';
 import { bindThis } from '@/decorators.js';
-import { isDuplicateKeyValueError } from '@/misc/is-duplicate-key-value-error.js';
 
 @Injectable()
 export class FederatedInstanceService implements OnApplicationShutdown {
@@ -26,9 +24,6 @@ export class FederatedInstanceService implements OnApplicationShutdown {
 		@Inject(DI.instancesRepository)
 		private instancesRepository: InstancesRepository,
 
-		@Inject(DI.db)
-		private readonly db: DataSource,
-
 		private utilityService: UtilityService,
 		private idService: IdService,
 	) {
@@ -58,11 +53,11 @@ export class FederatedInstanceService implements OnApplicationShutdown {
 		const cached = await this.federatedInstanceCache.get(host);
 		if (cached) return cached;
 
-		return await this.db.transaction(async tem => {
-			let index = await tem.findOneBy(MiInstance, { host });
-
-			if (index == null) {
-				await tem.insert(MiInstance, {
+		let index = await this.instancesRepository.findOneBy({ host });
+		if (index == null) {
+			await this.instancesRepository.createQueryBuilder('instance')
+				.insert()
+				.values({
 					id: this.idService.gen(),
 					host,
 					firstRetrievedAt: new Date(),
@@ -71,14 +66,15 @@ export class FederatedInstanceService implements OnApplicationShutdown {
 					isMediaSilenced: this.utilityService.isMediaSilencedHost(host),
 					isAllowListed: this.utilityService.isAllowListedHost(host),
 					isBubbled: this.utilityService.isBubbledHost(host),
-				});
+				})
+				.orIgnore()
+				.execute();
 
-				index = await tem.findOneByOrFail(MiInstance, { host });
-			}
+			index = await this.instancesRepository.findOneByOrFail({ host });
+		}
 
-			await this.federatedInstanceCache.set(host, index);
-			return index;
-		});
+		await this.federatedInstanceCache.set(host, index);
+		return index;
 	}
 
 	@bindThis
diff --git a/packages/backend/src/core/MetaService.ts b/packages/backend/src/core/MetaService.ts
index 5b6ee8920e..b4ccfec4cc 100644
--- a/packages/backend/src/core/MetaService.ts
+++ b/packages/backend/src/core/MetaService.ts
@@ -14,6 +14,7 @@ import type { GlobalEvents } from '@/core/GlobalEventService.js';
 import { FeaturedService } from '@/core/FeaturedService.js';
 import { MiInstance } from '@/models/Instance.js';
 import { diffArrays } from '@/misc/diff-arrays.js';
+import type { MetasRepository } from '@/models/_.js';
 import type { OnApplicationShutdown } from '@nestjs/common';
 
 @Injectable()
@@ -28,6 +29,9 @@ export class MetaService implements OnApplicationShutdown {
 		@Inject(DI.db)
 		private db: DataSource,
 
+		@Inject(DI.metasRepository)
+		private readonly metasRepository: MetasRepository,
+
 		private featuredService: FeaturedService,
 		private globalEventService: GlobalEventService,
 	) {
@@ -69,35 +73,31 @@ export class MetaService implements OnApplicationShutdown {
 	public async fetch(noCache = false): Promise<MiMeta> {
 		if (!noCache && this.cache) return this.cache;
 
-		return await this.db.transaction(async transactionalEntityManager => {
-			// 過去のバグでレコードが複数出来てしまっている可能性があるので新しいIDを優先する
-			const metas = await transactionalEntityManager.find(MiMeta, {
+		// 過去のバグでレコードが複数出来てしまっている可能性があるので新しいIDを優先する
+		let meta = await this.metasRepository.findOne({
+			order: {
+				id: 'DESC',
+			},
+		});
+
+		if (!meta) {
+			await this.metasRepository.createQueryBuilder('meta')
+				.insert()
+				.values({
+					id: 'x',
+				})
+				.orIgnore()
+				.execute();
+
+			meta = await this.metasRepository.findOneOrFail({
 				order: {
 					id: 'DESC',
 				},
 			});
+		}
 
-			const meta = metas[0];
-
-			if (meta) {
-				this.cache = meta;
-				return meta;
-			} else {
-				// metaが空のときfetchMetaが同時に呼ばれるとここが同時に呼ばれてしまうことがあるのでフェイルセーフなupsertを使う
-				const saved = await transactionalEntityManager
-					.upsert(
-						MiMeta,
-						{
-							id: 'x',
-						},
-						['id'],
-					)
-					.then((x) => transactionalEntityManager.findOneByOrFail(MiMeta, x.identifiers[0]));
-
-				this.cache = saved;
-				return saved;
-			}
-		});
+		this.cache = meta;
+		return meta;
 	}
 
 	@bindThis