diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a33c0c237..f49a4335b1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -50,6 +50,7 @@
 - Fix: チャットルームが削除された場合・チャットルームから抜けた場合に、未読状態が残り続けることがあるのを修正
 - Fix: ユーザ除外アンテナをインポートできない問題を修正
 - Fix: アンテナのセンシティブなチャンネルのノートを含むかどうかの情報がエクスポートされない問題を修正
+- Fix: 連合モードが「なし」の場合に、生成されるHTML内のactivity jsonへのリンクタグを省略するように
 
 
 ## 2025.5.0
diff --git a/packages/backend/src/server/web/ClientServerService.ts b/packages/backend/src/server/web/ClientServerService.ts
index 9a33d27d86..8ca61a497d 100644
--- a/packages/backend/src/server/web/ClientServerService.ts
+++ b/packages/backend/src/server/web/ClientServerService.ts
@@ -212,6 +212,7 @@ export class ClientServerService {
 			instanceUrl: this.config.url,
 			metaJson: htmlSafeJsonStringify(await this.metaEntityService.packDetailed(meta)),
 			now: Date.now(),
+			federationEnabled: this.meta.federation !== 'none',
 		};
 	}
 
diff --git a/packages/backend/src/server/web/views/note.pug b/packages/backend/src/server/web/views/note.pug
index fb659ce171..ea1993aed0 100644
--- a/packages/backend/src/server/web/views/note.pug
+++ b/packages/backend/src/server/web/views/note.pug
@@ -55,7 +55,8 @@ block meta
 	if note.next
 		link(rel='next' href=`${config.url}/notes/${note.next}`)
 
-	if !user.host
-		link(rel='alternate' href=url type='application/activity+json')
-	if note.uri
-		link(rel='alternate' href=note.uri type='application/activity+json')
+	if federationEnabled
+		if !user.host
+			link(rel='alternate' href=url type='application/activity+json')
+		if note.uri
+			link(rel='alternate' href=note.uri type='application/activity+json')
diff --git a/packages/backend/src/server/web/views/user.pug b/packages/backend/src/server/web/views/user.pug
index 2b0a7bab5c..b9f740f5b6 100644
--- a/packages/backend/src/server/web/views/user.pug
+++ b/packages/backend/src/server/web/views/user.pug
@@ -32,12 +32,13 @@ block meta
 		meta(name='twitter:creator' content=`@${profile.twitter.screenName}`)
 
 	if !sub
-		if !user.host
-			link(rel='alternate' href=`${config.url}/users/${user.id}` type='application/activity+json')
-		if user.uri
-			link(rel='alternate' href=user.uri type='application/activity+json')
-		if profile.url
-			link(rel='alternate' href=profile.url type='text/html')
+		if federationEnabled
+			if !user.host
+				link(rel='alternate' href=`${config.url}/users/${user.id}` type='application/activity+json')
+			if user.uri
+				link(rel='alternate' href=user.uri type='application/activity+json')
+			if profile.url
+				link(rel='alternate' href=profile.url type='text/html')
 
 	each m in me
 		link(rel='me' href=`${m}`)