diff --git a/superset/views/api.py b/superset/views/api.py
index 84c27d2fac18e..267d41dd75b8c 100644
--- a/superset/views/api.py
+++ b/superset/views/api.py
@@ -86,7 +86,7 @@ def query_form_data(self) -> FlaskResponse:  # pylint: disable=no-self-use
 
         update_time_range(form_data)
 
-        return json.dumps(form_data)
+        return self.json_response(form_data)
 
     @api
     @handle_api_exception
diff --git a/tests/integration_tests/charts/api_tests.py b/tests/integration_tests/charts/api_tests.py
index 2db0cc7de301a..c5e88426fad80 100644
--- a/tests/integration_tests/charts/api_tests.py
+++ b/tests/integration_tests/charts/api_tests.py
@@ -1424,6 +1424,20 @@ def test_get_time_range(self):
         self.assertEqual(rv.status_code, 200)
         self.assertEqual(len(data["result"]), 3)
 
+    def test_query_form_data(self):
+        """
+        Chart API: Test query form data
+        """
+        self.login(username="admin")
+        slice = db.session.query(Slice).first()
+        uri = f"api/v1/form_data/?slice_id={slice.id if slice else None}"
+        rv = self.client.get(uri)
+        data = json.loads(rv.data.decode("utf-8"))
+        self.assertEqual(rv.status_code, 200)
+        self.assertEqual(rv.content_type, "application/json")
+        if slice:
+            self.assertEqual(data["slice_id"], slice.id)
+
     @pytest.mark.usefixtures(
         "load_unicode_dashboard_with_slice",
         "load_energy_table_with_slice",