diff --git a/superset/views.py b/superset/views.py
index cf06776c98..155570b014 100755
--- a/superset/views.py
+++ b/superset/views.py
@@ -5,7 +5,6 @@ from __future__ import unicode_literals
 
 from datetime import datetime, timedelta
 import json
-import simplejson
 import logging
 import pickle
 import re
@@ -1405,8 +1404,7 @@ class Superset(BaseSupersetView):
             status = 500
 
         return Response(
-            simplejson.dumps(
-                payload, default=utils.json_int_dttm_ser, ignore_nan=True),
+            viz_obj.json_dumps(payload),
             status=status,
             mimetype="application/json")
 
diff --git a/superset/viz.py b/superset/viz.py
index 677f57a74d..611555997d 100755
--- a/superset/viz.py
+++ b/superset/viz.py
@@ -379,10 +379,7 @@ class BaseViz(object):
             payload['cached_dttm'] = datetime.now().isoformat().split('.')[0]
             logging.info("Caching for the next {} seconds".format(
                 cache_timeout))
-            data = json.dumps(
-                payload,
-                default=utils.json_int_dttm_ser, ignore_nan=True
-            )
+            data = self.json_dumps(payload)
             if PY3:
                 data = bytes(data, 'utf-8')
             try:
@@ -399,6 +396,9 @@ class BaseViz(object):
         payload['is_cached'] = is_cached
         return payload
 
+    def json_dumps(self, obj):
+        return json.dumps(obj, default=utils.json_int_dttm_ser, ignore_nan=True)
+
     @property
     def data(self):
         """This is the data object serialized to the js layer"""
@@ -538,6 +538,9 @@ class TableViz(BaseViz):
             columns=list(df.columns),
         )
 
+    def json_dumps(self, obj):
+        return json.dumps(obj, default=utils.json_iso_dttm_ser)
+
 
 class PivotTableViz(BaseViz):