diff --git a/packages/backend/src/core/activitypub/ApRendererService.ts b/packages/backend/src/core/activitypub/ApRendererService.ts
index 42ee5bc58a..e34872c714 100644
--- a/packages/backend/src/core/activitypub/ApRendererService.ts
+++ b/packages/backend/src/core/activitypub/ApRendererService.ts
@@ -469,6 +469,7 @@ export class ApRendererService {
 		};
 	}
 
+	// if you change this, also change `server/api/endpoints/i/update.ts`
 	@bindThis
 	public async renderPerson(user: MiLocalUser) {
 		const id = this.userEntityService.genLocalUserUri(user.id);
diff --git a/packages/backend/src/server/api/endpoints/i/update.ts b/packages/backend/src/server/api/endpoints/i/update.ts
index 8994c3fff6..f0e8dfc832 100644
--- a/packages/backend/src/server/api/endpoints/i/update.ts
+++ b/packages/backend/src/server/api/endpoints/i/update.ts
@@ -539,7 +539,9 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			}
 
 			// フォロワーにUpdateを配信
-			this.accountUpdateService.publishToFollowers(user.id);
+			if (this.userNeedsPublishing(user, updates) || this.profileNeedsPublishing(profile, updatedProfile)) {
+				this.accountUpdateService.publishToFollowers(user.id);
+			}
 
 			const urls = updatedProfile.fields.filter(x => x.value.startsWith('https://'));
 			for (const url of urls) {
@@ -581,4 +583,52 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 			// なにもしない
 		}
 	}
+
+	// these two methods need to be kept in sync with
+	// `ApRendererService.renderPerson`
+	private userNeedsPublishing(oldUser: MiLocalUser, newUser: Partial<MiUser>): boolean {
+		for (const field of ['avatarId', 'bannerId', 'backgroundId', 'isBot', 'username', 'name', 'isLocked', 'isExplorable', 'isCat', 'noindex', 'speakAsCat', 'movedToUri', 'alsoKnownAs'] as (keyof MiUser)[]) {
+			if (newUser.hasOwnProperty(field) && oldUser[field] !== newUser[field]) {
+				return true;
+			}
+		}
+		for (const arrayField of ['emojis', 'tags'] as (keyof MiUser)[]) {
+			if (newUser.hasOwnProperty(arrayField) !== oldUser.hasOwnProperty(arrayField)) {
+				return true;
+			}
+
+			const oldArray = oldUser[arrayField] ?? [];
+			const newArray = newUser[arrayField] ?? [];
+			if (!Array.isArray(oldArray) || !Array.isArray(newArray)) {
+				return true;
+			}
+			if (oldArray.join("\0") !== newArray.join("\0")) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	private profileNeedsPublishing(oldProfile: MiUserProfile, newProfile: Partial<MiUserProfile>): boolean {
+		for (const field of ['description', 'followedMessage', 'birthday', 'location', 'listenbrainz'] as (keyof MiUserProfile)[]) {
+			if (newProfile.hasOwnProperty(field) && oldProfile[field] !== newProfile[field]) {
+				return true;
+			}
+		}
+		for (const arrayField of ['fields'] as (keyof MiUserProfile)[]) {
+			if (newProfile.hasOwnProperty(arrayField) !== oldProfile.hasOwnProperty(arrayField)) {
+				return true;
+			}
+
+			const oldArray = oldProfile[arrayField] ?? [];
+			const newArray = newProfile[arrayField] ?? [];
+			if (!Array.isArray(oldArray) || !Array.isArray(newArray)) {
+				return true;
+			}
+			if (oldArray.join("\0") !== newArray.join("\0")) {
+				return true;
+			}
+		}
+		return false;
+	}
 }