diff --git a/app.rb b/app.rb
index dc43868..aa82f35 100644
--- a/app.rb
+++ b/app.rb
@@ -47,7 +47,8 @@ class App < Roda
     r.on "links" do
       r.post do
         if 'application/json' != r.headers['CONTENT_TYPE']
-          return {message: "Not a valid JSON request"}.to_json
+          response.status = 400
+          return {message: "not a valid json request"}.to_json
         end
 
         url = r.params['url']