diff --git a/packages/backend/src/misc/error.ts b/packages/backend/src/misc/error.ts
deleted file mode 100644
index 57df15c30b..0000000000
--- a/packages/backend/src/misc/error.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-/*
- * SPDX-FileCopyrightText: MomentQYC and other misskey contributors
- * SPDX-License-Identifier: AGPL-3.0-only
- */
-import { FastifyReply, FastifyRequest } from 'fastify';
-
-export async function ErrorHandler(error: Error, request: FastifyRequest, reply: FastifyReply): Promise<void> {
-	if (process.env.NODE_ENV === 'production') {
-		error.stack = undefined;
-	}
-	reply.send(error);
-	throw error;
-}
diff --git a/packages/backend/src/misc/fastify-reply-error.ts b/packages/backend/src/misc/fastify-reply-error.ts
index 8edfa87bdc..7c889bab7a 100644
--- a/packages/backend/src/misc/fastify-reply-error.ts
+++ b/packages/backend/src/misc/fastify-reply-error.ts
@@ -12,9 +12,5 @@ export class FastifyReplyError extends Error {
 		super(message);
 		this.message = message;
 		this.statusCode = statusCode;
-
-		if (process.env.NODE_ENV === 'production') {
-			Object.defineProperty(this, 'stack', { value: undefined });
-		}
 	}
 }
diff --git a/packages/backend/src/server/ServerService.ts b/packages/backend/src/server/ServerService.ts
index 1cf7c7e859..b40eeb31b1 100644
--- a/packages/backend/src/server/ServerService.ts
+++ b/packages/backend/src/server/ServerService.ts
@@ -22,7 +22,6 @@ import { UserEntityService } from '@/core/entities/UserEntityService.js';
 import { LoggerService } from '@/core/LoggerService.js';
 import { bindThis } from '@/decorators.js';
 import { MetaService } from '@/core/MetaService.js';
-import { ErrorHandler } from '@/misc/error.js';
 import { ActivityPubServerService } from './ActivityPubServerService.js';
 import { NodeinfoServerService } from './NodeinfoServerService.js';
 import { ApiServerService } from './api/ApiServerService.js';
@@ -77,7 +76,6 @@ export class ServerService implements OnApplicationShutdown {
 			logger: !['production', 'test'].includes(process.env.NODE_ENV ?? ''),
 		});
 		this.#fastify = fastify;
-		fastify.setErrorHandler(ErrorHandler);
 
 		// HSTS
 		// 6months (15552000sec)
diff --git a/packages/backend/src/server/web/ClientServerService.ts b/packages/backend/src/server/web/ClientServerService.ts
index 7614b2cf9b..7e9f2a5eba 100644
--- a/packages/backend/src/server/web/ClientServerService.ts
+++ b/packages/backend/src/server/web/ClientServerService.ts
@@ -682,13 +682,12 @@ export class ClientServerService {
 
 		fastify.setErrorHandler(async (error, request, reply) => {
 			const errId = randomUUID();
-			const stack = (process.env.NODE_ENV === 'production') ? '' : error.stack;
 			this.clientLoggerService.logger.error(`Internal error occurred in ${request.routerPath}: ${error.message}`, {
 				path: request.routerPath,
 				params: request.params,
 				query: request.query,
 				code: error.name,
-				stack,
+				stack: error.stack,
 				id: errId,
 			});
 			reply.code(500);