diff --git a/packages/backend/src/core/activitypub/ApDbResolverService.ts b/packages/backend/src/core/activitypub/ApDbResolverService.ts
index 4209c6b3e3..8c97cc8ce8 100644
--- a/packages/backend/src/core/activitypub/ApDbResolverService.ts
+++ b/packages/backend/src/core/activitypub/ApDbResolverService.ts
@@ -176,10 +176,17 @@ export class ApDbResolverService implements OnApplicationShutdown {
 	 */
 	@bindThis
 	public async refetchPublicKeyForApId(user: MiRemoteUser): Promise<MiUserPublickey | null> {
-		this.apLoggerService.logger.info('Re-fetching public key for user', { userId: user.id });
+		this.apLoggerService.logger.debug('Re-fetching public key for user', { userId: user.id, uri: user.uri });
 		await this.apPersonService.updatePerson(user.uri);
+
 		const key = await this.userPublickeysRepository.findOneBy({ userId: user.id });
 		this.publicKeyByUserIdCache.set(user.id, key);
+
+		if (key) {
+			this.apLoggerService.logger.info('Re-fetched public key for user', { userId: user.id, uri: user.uri });
+		} else {
+			this.apLoggerService.logger.warn('Failed to re-fetch key for user', { userId: user.id, uri: user.uri });
+		}
 		return key;
 	}
 
diff --git a/packages/backend/src/queue/processors/InboxProcessorService.ts b/packages/backend/src/queue/processors/InboxProcessorService.ts
index 8c116f82b9..11b00bb683 100644
--- a/packages/backend/src/queue/processors/InboxProcessorService.ts
+++ b/packages/backend/src/queue/processors/InboxProcessorService.ts
@@ -118,6 +118,7 @@ export class InboxProcessorService implements OnApplicationShutdown {
 		// HTTP-Signatureの検証
 		let httpSignatureValidated = httpSignature.verifySignature(signature, authUser.key.keyPem);
 
+		// maybe they changed their key? refetch it
 		if (!httpSignatureValidated) {
 			authUser.key = await this.apDbResolverService.refetchPublicKeyForApId(authUser.user);
 			if (authUser.key != null) {
diff --git a/packages/backend/src/server/ActivityPubServerService.ts b/packages/backend/src/server/ActivityPubServerService.ts
index 8d52cf27e6..52592c47c6 100644
--- a/packages/backend/src/server/ActivityPubServerService.ts
+++ b/packages/backend/src/server/ActivityPubServerService.ts
@@ -205,15 +205,11 @@ export class ActivityPubServerService {
 
 		let httpSignatureValidated = httpSignature.verifySignature(signature, authUser.key.keyPem);
 
+		// maybe they changed their key? refetch it
 		if (!httpSignatureValidated) {
-			this.authlogger.info(`${logPrefix} failed to validate signature, re-fetching the key for ${authUser.user.uri}`);
-			// maybe they changed their key? refetch it
 			authUser.key = await this.apDbResolverService.refetchPublicKeyForApId(authUser.user);
-
 			if (authUser.key != null) {
 				httpSignatureValidated = httpSignature.verifySignature(signature, authUser.key.keyPem);
-			} else {
-				this.authlogger.warn(`${logPrefix} failed to re-fetch key for ${authUser.user}`);
 			}
 		}