diff --git a/packages/backend/src/postgres.ts b/packages/backend/src/postgres.ts
index b06895fcc9..be225ef1ed 100644
--- a/packages/backend/src/postgres.ts
+++ b/packages/backend/src/postgres.ts
@@ -5,7 +5,7 @@
 
 // https://github.com/typeorm/typeorm/issues/2400
 import pg from 'pg';
-import { DataSource, Logger, type QueryRunner } from 'typeorm';
+import { DataSource, EntityManager, Logger, type QueryRunner } from 'typeorm';
 import * as highlight from 'cli-highlight';
 import { entities as charts } from '@/core/chart/entities.js';
 import { Config } from '@/config.js';
@@ -262,6 +262,33 @@ export const entities = [
 
 const log = process.env.NODE_ENV !== 'production';
 
+/**
+ * Execute query with extended timeout.
+ * This can be used to execute long-running queries like deleting many rows CASCADE-ly.
+ *
+ * TODO: consider remove this function when we removed CASCADE delete.
+ */
+export async function extendTimeoutQuery(dataSource: DataSource, query: (manager: EntityManager) => Promise<void>): Promise<void> {
+	const queryRunner = dataSource.createQueryRunner('master');
+	const manager = dataSource.createEntityManager(queryRunner);
+	const extendedTimeout = 1000 * 100; // 100 sec for now. How long should it be?
+	try {
+		await queryRunner.connect();
+		try {
+			// it looks postgres doesn't support statement_timeout with placeholder
+			// await manager.query(`set statement_timeout to $1`, [extendedTimeout]);
+			await manager.query(`set statement_timeout to ${extendedTimeout}`);
+			await query(manager);
+		} finally {
+			await manager.query(`set statement_timeout to ${default_statement_timeout}`);
+		}
+	} finally {
+		await queryRunner.release();
+	}
+}
+
+export const default_statement_timeout = 1000 * 10;
+
 export function createPostgresDataSource(config: Config) {
 	return new DataSource({
 		type: 'postgres',
@@ -271,7 +298,7 @@ export function createPostgresDataSource(config: Config) {
 		password: config.db.pass,
 		database: config.db.db,
 		extra: {
-			statement_timeout: 1000 * 10,
+			statement_timeout: default_statement_timeout,
 			...config.db.extra,
 		},
 		...(config.dbReplications ? {
diff --git a/packages/backend/src/queue/processors/DeleteAccountProcessorService.ts b/packages/backend/src/queue/processors/DeleteAccountProcessorService.ts
index 14a53e0c42..55aaff8cf9 100644
--- a/packages/backend/src/queue/processors/DeleteAccountProcessorService.ts
+++ b/packages/backend/src/queue/processors/DeleteAccountProcessorService.ts
@@ -4,16 +4,18 @@
  */
 
 import { Inject, Injectable } from '@nestjs/common';
-import { MoreThan } from 'typeorm';
+import { DataSource, MoreThan } from 'typeorm';
 import { DI } from '@/di-symbols.js';
 import type { DriveFilesRepository, NotesRepository, UserProfilesRepository, UsersRepository } from '@/models/_.js';
+import { MiUser } from '@/models/User.js';
 import type Logger from '@/logger.js';
 import { DriveService } from '@/core/DriveService.js';
 import type { MiDriveFile } from '@/models/DriveFile.js';
-import type { MiNote } from '@/models/Note.js';
+import { MiNote } from '@/models/Note.js';
 import { EmailService } from '@/core/EmailService.js';
 import { bindThis } from '@/decorators.js';
 import { SearchService } from '@/core/SearchService.js';
+import { extendTimeoutQuery } from '@/postgres.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import type * as Bull from 'bullmq';
 import type { DbUserDeleteJobData } from '../types.js';
@@ -23,6 +25,9 @@ export class DeleteAccountProcessorService {
 	private logger: Logger;
 
 	constructor(
+		@Inject(DI.db)
+		private db: DataSource,
+
 		@Inject(DI.usersRepository)
 		private usersRepository: UsersRepository,
 
@@ -73,7 +78,9 @@ export class DeleteAccountProcessorService {
 
 				cursor = notes.at(-1)?.id ?? null;
 
-				await this.notesRepository.delete(notes.map(note => note.id));
+				await extendTimeoutQuery(this.db, async (manager) => {
+					await manager.delete(MiNote, notes.map(note => note.id));
+				});
 
 				for (const note of notes) {
 					await this.searchService.unindexNote(note);
@@ -125,7 +132,9 @@ export class DeleteAccountProcessorService {
 		if (job.data.soft) {
 		// nop
 		} else {
-			await this.usersRepository.delete(job.data.user.id);
+			await extendTimeoutQuery(this.db, async (manager) => {
+				await manager.delete(MiUser, job.data.user.id);
+			});
 		}
 
 		return 'Account deleted';