diff --git a/superset/models/helpers.py b/superset/models/helpers.py
index b603f0bb3cea..ec7ec506e17f 100644
--- a/superset/models/helpers.py
+++ b/superset/models/helpers.py
@@ -1979,7 +1979,7 @@ def processing_time_offsets(  # pylint: disable=too-many-locals,too-many-stateme
             if offset_metrics_df.empty:
                 offset_metrics_df = pd.DataFrame(
                     {
-                        col: [np.NaN]
+                        col: [np.nan]
                         for col in join_keys + list(metrics_mapping.values())
                     }
                 )