diff --git a/superset/viz.py b/superset/viz.py
index 8b88907292922..a70d9de22df23 100644
--- a/superset/viz.py
+++ b/superset/viz.py
@@ -1374,7 +1374,7 @@ def get_data(self, df: pd.DataFrame) -> VizData:
         metric = utils.get_metric_name(form_data["metric"])
         secondary_metric = (
             utils.get_metric_name(form_data["secondary_metric"])
-            if "secondary_metric" in form_data
+            if form_data.get("secondary_metric")
             else None
         )
         if metric == secondary_metric or secondary_metric is None:
@@ -1582,7 +1582,7 @@ def get_data(self, df: pd.DataFrame) -> VizData:
         metric = utils.get_metric_name(self.form_data["metric"])
         secondary_metric = (
             utils.get_metric_name(self.form_data["secondary_metric"])
-            if "secondary_metric" in self.form_data
+            if self.form_data.get("secondary_metric")
             else None
         )
         columns = ["country", "m1", "m2"]