diff --git a/packages/backend/src/server/ActivityPubServerService.ts b/packages/backend/src/server/ActivityPubServerService.ts
index e76a8ef54..d0df57121 100644
--- a/packages/backend/src/server/ActivityPubServerService.ts
+++ b/packages/backend/src/server/ActivityPubServerService.ts
@@ -88,6 +88,7 @@ export class ActivityPubServerService {
 
 	@bindThis
 	private inbox(request: FastifyRequest, reply: FastifyReply) {
+		let signature;
 
 		try {
 			signature = httpSignature.parseRequest(request.raw, { 'headers': [] });