diff --git a/superset-frontend/src/views/CRUD/alert/AlertReportModal.tsx b/superset-frontend/src/views/CRUD/alert/AlertReportModal.tsx
index 4e2d288021..26a2df4aba 100644
--- a/superset-frontend/src/views/CRUD/alert/AlertReportModal.tsx
+++ b/superset-frontend/src/views/CRUD/alert/AlertReportModal.tsx
@@ -611,11 +611,9 @@ const AlertReportModal: FunctionComponent<AlertReportModalProps> = ({
       validator_config_json: conditionNotNull
         ? {}
         : currentAlert?.validator_config_json,
-      chart: contentType === 'chart' ? currentAlert?.chart?.value : undefined,
+      chart: contentType === 'chart' ? currentAlert?.chart?.value : null,
       dashboard:
-        contentType === 'dashboard'
-          ? currentAlert?.dashboard?.value
-          : undefined,
+        contentType === 'dashboard' ? currentAlert?.dashboard?.value : null,
       database: currentAlert?.database?.value,
       owners: (currentAlert?.owners || []).map(
         owner => (owner as MetaObject).value,
@@ -869,10 +867,12 @@ const AlertReportModal: FunctionComponent<AlertReportModalProps> = ({
 
   const onDashboardChange = (dashboard: SelectValue) => {
     updateAlertState('dashboard', dashboard || undefined);
+    updateAlertState('chart', null);
   };
 
   const onChartChange = (chart: SelectValue) => {
     updateAlertState('chart', chart || undefined);
+    updateAlertState('dashboard', null);
   };
 
   const onActiveSwitch = (checked: boolean) => {
diff --git a/superset/reports/schemas.py b/superset/reports/schemas.py
index fe9a2fbe7c..94c99b6180 100644
--- a/superset/reports/schemas.py
+++ b/superset/reports/schemas.py
@@ -220,8 +220,8 @@ class ReportSchedulePutSchema(Schema):
         required=False,
         allow_none=True,
     )
-    chart = fields.Integer(required=False)
-    dashboard = fields.Integer(required=False)
+    chart = fields.Integer(required=False, allow_none=True)
+    dashboard = fields.Integer(required=False, allow_none=True)
     database = fields.Integer(required=False)
     owners = fields.List(fields.Integer(description=owners_description), required=False)
     validator_type = fields.String(