diff --git a/demo/tests/test_integration.py b/demo/tests/test_integration.py
index 25420de1..270178b0 100644
--- a/demo/tests/test_integration.py
+++ b/demo/tests/test_integration.py
@@ -409,8 +409,9 @@ def test_validate_data_ok(self):
             parameters, format='json'
         )
         self.assertEqual(res.status_code, 204)
+        self.assertIn('application/json', str(res.serialize_headers()))
 
-    def test_validate_does_not_exist(self):
+    def test_formidable_does_not_exist(self):
         parameters = {
             'first_name': 'Guillaume',
             'last_name': 'Gérard',
@@ -438,6 +439,7 @@ def test_validate_data_ko(self):
         self.assertEqual(res.status_code, 400)
         errors = res.data
         self.assertIn('first_name', errors)
+        self.assertIn('application/json', str(res.serialize_headers()))
 
     def test_validate_with_mandatory_file(self):
         class WithFile(FormidableForm):
diff --git a/formidable/views.py b/formidable/views.py
index d5d752dc..fbc91f66 100644
--- a/formidable/views.py
+++ b/formidable/views.py
@@ -266,7 +266,7 @@ def get_form_class_kwargs(self):
         }
 
     def form_valid(self, form):
-        return Response(status=204)
+        return Response({}, status=204)
 
     def form_invalid(self, form):
         # TODO change response when UI ready