diff --git a/src/server/activitypub.ts b/src/server/activitypub.ts
index d04ffd38f..1007790ca 100644
--- a/src/server/activitypub.ts
+++ b/src/server/activitypub.ts
@@ -25,7 +25,7 @@ function inbox(ctx: Router.IRouterContext) {
 	ctx.req.headers.authorization = 'Signature ' + ctx.req.headers.signature;
 
 	try {
-		signature = httpSignature.parseRequest(ctx.req);
+		signature = httpSignature.parseRequest(ctx.req, { 'headers': [] });
 	} catch (e) {
 		ctx.status = 401;
 		return;