diff --git a/packages/backend/src/core/QueueService.ts b/packages/backend/src/core/QueueService.ts
index 7ba1853f84..1e96adedfd 100644
--- a/packages/backend/src/core/QueueService.ts
+++ b/packages/backend/src/core/QueueService.ts
@@ -15,7 +15,7 @@ import type { Antenna } from '@/server/api/endpoints/i/import-antennas.js';
 import type { DbQueue, DeliverQueue, EndedPollNotificationQueue, InboxQueue, ObjectStorageQueue, RelationshipQueue, SystemQueue, WebhookDeliverQueue } from './QueueModule.js';
 import type { DbJobData, DeliverJobData, RelationshipJobData, ThinUser } from '../queue/types.js';
 import type * as Bull from 'bullmq';
-import type { ParsedSignature } from '@misskey-dev/node-http-message-signatures';
+import { genRFC3230DigestHeader, type ParsedSignature } from '@misskey-dev/node-http-message-signatures';
 
 @Injectable()
 export class QueueService {
@@ -81,6 +81,7 @@ export class QueueService {
 				id: user.id,
 			},
 			content: contentBody,
+			digest: await genRFC3230DigestHeader(contentBody, 'SHA-256'),
 			to,
 			isSharedInbox,
 		};
diff --git a/packages/backend/src/core/activitypub/ApRequestService.ts b/packages/backend/src/core/activitypub/ApRequestService.ts
index 0e96a80165..8469dfbce4 100644
--- a/packages/backend/src/core/activitypub/ApRequestService.ts
+++ b/packages/backend/src/core/activitypub/ApRequestService.ts
@@ -28,7 +28,7 @@ type PrivateKey = {
 	keyId: string;
 };
 
-export async function createSignedPost(args: { level: string; key: PrivateKey; url: string; body: string; additionalHeaders: Record<string, string> }) {
+export async function createSignedPost(args: { level: string; key: PrivateKey; url: string; body: string; digest?: string, additionalHeaders: Record<string, string> }) {
 	const u = new URL(args.url);
 	const request: RequestLike = {
 		url: u.href,
@@ -40,9 +40,9 @@ export async function createSignedPost(args: { level: string; key: PrivateKey; u
 			...args.additionalHeaders,
 		},
 	};
-
+c
 	// TODO: httpMessageSignaturesImplementationLevelによって新規格で通信をするようにする
-	const digestHeader = await genRFC3230DigestHeader(args.body, 'SHA-256');
+	const digestHeader = args.digest ?? await genRFC3230DigestHeader(args.body, 'SHA-256');
 	request.headers['Digest'] = digestHeader;
 
 	const result = await signAsDraftToRequest(request, args.key, ['(request-target)', 'date', 'host', 'digest']);
@@ -105,7 +105,7 @@ export class ApRequestService {
 	}
 
 	@bindThis
-	public async signedPost(user: { id: MiUser['id'] }, url: string, object: unknown, level: string): Promise<void> {
+	public async signedPost(user: { id: MiUser['id'] }, url: string, object: unknown, level: string, digest?: string): Promise<void> {
 		const body = typeof object === 'string' ? object : JSON.stringify(object);
 		const key = await this.getPrivateKey(user.id, level);
 		const req = await createSignedPost({
@@ -116,6 +116,7 @@ export class ApRequestService {
 			additionalHeaders: {
 				'User-Agent': this.config.userAgent,
 			},
+			digest,
 		});
 
 		this.logger.debug('create signed post', {
diff --git a/packages/backend/src/queue/processors/DeliverProcessorService.ts b/packages/backend/src/queue/processors/DeliverProcessorService.ts
index 6bbe7a4973..8f3782a048 100644
--- a/packages/backend/src/queue/processors/DeliverProcessorService.ts
+++ b/packages/backend/src/queue/processors/DeliverProcessorService.ts
@@ -76,7 +76,7 @@ export class DeliverProcessorService {
 			await this.fetchInstanceMetadataService.fetchInstanceMetadata(_server).then(() => {});
 			const server = await this.federatedInstanceService.fetch(host);
 
-			await this.apRequestService.signedPost(job.data.user, job.data.to, job.data.content, server.httpMessageSignaturesImplementationLevel);
+			await this.apRequestService.signedPost(job.data.user, job.data.to, job.data.content, server.httpMessageSignaturesImplementationLevel, job.data.digest);
 
 			// Update stats
 			if (server.isNotResponding) {
diff --git a/packages/backend/src/queue/types.ts b/packages/backend/src/queue/types.ts
index fcae4c2596..135bccb60c 100644
--- a/packages/backend/src/queue/types.ts
+++ b/packages/backend/src/queue/types.ts
@@ -32,6 +32,8 @@ export type DeliverJobData = {
 	user: ThinUser;
 	/** Activity */
 	content: string;
+	/** Digest header */
+	digest: string;
 	/** inbox URL to deliver */
 	to: string;
 	/** whether it is sharedInbox */