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);
 	}