diff --git a/packages/backend/src/remote/activitypub/audience.ts b/packages/backend/src/remote/activitypub/audience.ts
index 766e05148..36c988eff 100644
--- a/packages/backend/src/remote/activitypub/audience.ts
+++ b/packages/backend/src/remote/activitypub/audience.ts
@@ -96,7 +96,7 @@ function groupingAudience(ids: string[], actor: CacheableRemoteUser) {
 function isPublic(id: string) {
 	return [
 		"https://www.w3.org/ns/activitystreams#Public",
-		"as#Public",
+		"as:Public",
 		"Public",
 	].includes(id);
 }