diff --git a/packages/backend/src/misc/fetch.ts b/packages/backend/src/misc/fetch.ts
index b24eecd86..661716e25 100644
--- a/packages/backend/src/misc/fetch.ts
+++ b/packages/backend/src/misc/fetch.ts
@@ -35,7 +35,7 @@ export async function getHtml(url: string, accept = 'text/html, */*', timeout =
 	return await res.text();
 }
 
-export async function getResponse(args: { url: string, method: string, body?: string, headers: Record<string, string>, timeout?: number, size?: number }) {
+export async function getResponse(args: { url: string, method: string, body?: string, headers: Record<string, string>, timeout?: number, size?: number, redirect: 'follow' | 'manual' | 'error' = 'follow' }) {
 	const timeout = args.timeout || 10 * SECOND;
 
 	const controller = new AbortController();
@@ -47,8 +47,9 @@ export async function getResponse(args: { url: string, method: string, body?: st
 		method: args.method,
 		headers: args.headers,
 		body: args.body,
+		redirect: args.redirect,
 		timeout,
-		size: args.size || 10 * 1024 * 1024,
+		size: args.size || 10 * 1024 * 1024, // 10 MiB
 		agent: getAgentByUrl,
 		signal: controller.signal,
 	});
diff --git a/packages/backend/src/remote/activitypub/request.ts b/packages/backend/src/remote/activitypub/request.ts
index ccdd30a00..dd1aeccea 100644
--- a/packages/backend/src/remote/activitypub/request.ts
+++ b/packages/backend/src/remote/activitypub/request.ts
@@ -1,3 +1,4 @@
+import { URL } from 'node:url';
 import config from '@/config/index.js';
 import { getUserKeypair } from '@/misc/keypair-store.js';
 import { User } from '@/models/entities/user.js';
@@ -37,22 +38,32 @@ export async function request(user: { id: User['id'] }, url: string, object: any
 export async function signedGet(url: string, user: { id: User['id'] }): Promise<any> {
 	const keypair = await getUserKeypair(user.id);
 
-	const req = createSignedGet({
-		key: {
-			privateKeyPem: keypair.privateKey,
-			keyId: `${config.url}/users/${user.id}#main-key`,
-		},
-		url,
-		additionalHeaders: {
-			'User-Agent': config.userAgent,
-		},
-	});
+	for (let redirects = 0; redirects < 3; redirects++) {
+		const req = createSignedGet({
+			key: {
+				privateKeyPem: keypair.privateKey,
+				keyId: `${config.url}/users/${user.id}#main-key`,
+			},
+			url,
+			additionalHeaders: {
+				'User-Agent': config.userAgent,
+			},
+		});
 
-	const res = await getResponse({
-		url,
-		method: req.request.method,
-		headers: req.request.headers,
-	});
+		const res = await getResponse({
+			url,
+			method: req.request.method,
+			headers: req.request.headers,
+		});
 
-	return await res.json();
+		if (res.status >= 300 && res.status < 400) {
+			// Have been redirected, need to make a new signature.
+			// Use Location header and fetched URL as the base URL.
+			url = new URL(res.headers.get('Location'), url).href;
+		} else {
+			return await res.json();
+		}
+	}
+
+	throw new Error('too many redirects');
 }