diff --git a/superset/views/core.py b/superset/views/core.py
index 109e6b6850..05e74867b8 100755
--- a/superset/views/core.py
+++ b/superset/views/core.py
@@ -1107,7 +1107,9 @@ class Superset(BaseSupersetView):
         if not self.datasource_access(datasource):
             return json_error_response(DATASOURCE_ACCESS_ERR)
 
-        payload = json.dumps(datasource.values_for_column(column))
+        payload = json.dumps(
+            datasource.values_for_column(column),
+            default=utils.json_int_dttm_ser)
         return json_success(payload)
 
     def save_or_overwrite_slice(