diff --git a/influxdb/_dataframe_client.py b/influxdb/_dataframe_client.py
index 2444a77f..511253a1 100644
--- a/influxdb/_dataframe_client.py
+++ b/influxdb/_dataframe_client.py
@@ -236,7 +236,7 @@ def _convert_dataframe_to_json(dataframe,
             field_columns = list(
                 set(dataframe.columns).difference(set(tag_columns)))
 
-        dataframe.index = dataframe.index.to_datetime()
+        dataframe.index = dataframe.index.to_pydatetime()
         if dataframe.index.tzinfo is None:
             dataframe.index = dataframe.index.tz_localize('UTC')