diff --git a/app/controllers/protocols_controller.rb b/app/controllers/protocols_controller.rb
index 181e76a37..0deb95d4e 100644
--- a/app/controllers/protocols_controller.rb
+++ b/app/controllers/protocols_controller.rb
@@ -1145,7 +1145,7 @@ class ProtocolsController < ApplicationController
     unless @protocol.present? &&
            (can_read_protocol_in_module?(@protocol) ||
            can_read_protocol_in_repository?(@protocol))
-      respond_to { |f| f.json { render json: {}, status: :unauthorized } }
+      render_403
     end
   end