diff --git a/CHANGELOG.md b/CHANGELOG.md
index 778438729..744846d99 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,7 +8,7 @@
 -
 
 ### Server
--
+- Fix: 外部サーバーの投稿がタイムラインに表示されないことがある問題を修正
 
 -->
 ## 13.x.x (unreleased)
diff --git a/packages/backend/src/core/activitypub/ApAudienceService.ts b/packages/backend/src/core/activitypub/ApAudienceService.ts
index a4ab5eae2..f2d84341f 100644
--- a/packages/backend/src/core/activitypub/ApAudienceService.ts
+++ b/packages/backend/src/core/activitypub/ApAudienceService.ts
@@ -95,7 +95,7 @@ export class ApAudienceService {
 	private isPublic(id: string): boolean {
 		return [
 			'https://www.w3.org/ns/activitystreams#Public',
-			'as#Public',
+			'as:Public',
 			'Public',
 		].includes(id);
 	}