diff --git a/packages/backend/src/queue/processors/InboxProcessorService.ts b/packages/backend/src/queue/processors/InboxProcessorService.ts
index f51c9f140d..b57f64f16a 100644
--- a/packages/backend/src/queue/processors/InboxProcessorService.ts
+++ b/packages/backend/src/queue/processors/InboxProcessorService.ts
@@ -108,7 +108,7 @@ export class InboxProcessorService {
 
 		// また、signatureのsignerは、activity.actorと一致する必要がある
 		if (!httpSignatureValidated || authUser.user.uri !== activity.actor) {
-			let renewKeyFailed = false;
+			let renewKeyFailed = authUser.user.uri !== activity.actor ? true : false;
 			
 			if (!httpSignatureValidated) {
 				authUser.key = await this.apDbResolverService.refetchPublicKeyForApId(authUser.user);