diff --git a/packages/backend/src/queue/processors/InboxProcessorService.ts b/packages/backend/src/queue/processors/InboxProcessorService.ts
index 94163a2495..23e377d790 100644
--- a/packages/backend/src/queue/processors/InboxProcessorService.ts
+++ b/packages/backend/src/queue/processors/InboxProcessorService.ts
@@ -114,7 +114,7 @@ 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) {
+		if (httpSignatureValidated !== true || authUser.user.uri !== activity.actor) {
 			// 一致しなくても、でもLD-Signatureがありそうならそっちも見る
 			if (activity.signature?.creator) {
 				if (activity.signature.type !== 'RsaSignature2017') {
diff --git a/packages/backend/src/server/ActivityPubServerService.ts b/packages/backend/src/server/ActivityPubServerService.ts
index 1dbb94a2c2..78b89e8684 100644
--- a/packages/backend/src/server/ActivityPubServerService.ts
+++ b/packages/backend/src/server/ActivityPubServerService.ts
@@ -103,7 +103,7 @@ export class ActivityPubServerService {
 		let signature: ReturnType<typeof parseRequestSignature>;
 
 		const verifyDigest = await verifyDigestHeader(request.raw, request.rawBody || '', true);
-		if (!verifyDigest) {
+		if (verifyDigest !== true) {
 			reply.code(401);
 			return;
 		}