diff --git a/src/middleware/activitypub.js b/src/middleware/activitypub.js
index 12761763a1..79c3e19fe3 100644
--- a/src/middleware/activitypub.js
+++ b/src/middleware/activitypub.js
@@ -46,3 +46,8 @@ middleware.validate = async function (req, res, next) {
 
 	next();
 };
+
+middleware.configureResponse = async function (req, res, next) {
+	res.header('Content-Type', 'application/activity+json');
+	next();
+};