diff --git a/x-pack/plugins/alerting/server/alerts_client/legacy_alerts_client.test.ts b/x-pack/plugins/alerting/server/alerts_client/legacy_alerts_client.test.ts
index 5da807ddba65dd..3fb1877756d156 100644
--- a/x-pack/plugins/alerting/server/alerts_client/legacy_alerts_client.test.ts
+++ b/x-pack/plugins/alerting/server/alerts_client/legacy_alerts_client.test.ts
@@ -12,7 +12,7 @@ import { createAlertFactory, getPublicAlertFactory } from '../alert/create_alert
 import { Alert } from '../alert/alert';
 import { alertingEventLoggerMock } from '../lib/alerting_event_logger/alerting_event_logger.mock';
 import { ruleRunMetricsStoreMock } from '../lib/rule_run_metrics_store.mock';
-import { getAlertsForNotification, processAlerts, setFlapping } from '../lib';
+import { getAlertsForNotification, processAlerts } from '../lib';
 import { logAlerts } from '../task_runner/log_alerts';
 import { DEFAULT_FLAPPING_SETTINGS } from '../../common/rules_settings';
 
@@ -254,19 +254,6 @@ describe('Legacy Alerts Client', () => {
       flappingSettings: DEFAULT_FLAPPING_SETTINGS,
     });
 
-    expect(setFlapping).toHaveBeenCalledWith(
-      {
-        enabled: true,
-        lookBackWindow: 20,
-        statusChangeThreshold: 4,
-      },
-      {
-        '1': new Alert<AlertInstanceContext, AlertInstanceContext>('1', testAlert1),
-        '2': new Alert<AlertInstanceContext, AlertInstanceContext>('2', testAlert2),
-      },
-      {}
-    );
-
     expect(getAlertsForNotification).toHaveBeenCalledWith(
       {
         enabled: true,
diff --git a/x-pack/plugins/alerting/server/alerts_client/legacy_alerts_client.ts b/x-pack/plugins/alerting/server/alerts_client/legacy_alerts_client.ts
index f31e39c8e48ea1..8fce6782cd2f17 100644
--- a/x-pack/plugins/alerting/server/alerts_client/legacy_alerts_client.ts
+++ b/x-pack/plugins/alerting/server/alerts_client/legacy_alerts_client.ts
@@ -177,12 +177,6 @@ export class LegacyAlertsClient<
       canSetRecoveryContext: this.options.ruleType.doesSetRecoveryContext ?? false,
       shouldPersistAlerts: shouldLogAndScheduleActionsForAlerts,
     });
-
-    setFlapping<State, Context, ActionGroupIds, RecoveryActionGroupId>(
-      flappingSettings,
-      this.processedAlerts.active,
-      this.processedAlerts.recovered
-    );
   }
 
   public getProcessedAlerts(
@@ -213,4 +207,12 @@ export class LegacyAlertsClient<
   public getExecutorServices() {
     return getPublicAlertFactory(this.alertFactory!);
   }
+
+  public setFlapping(flappingSettings: RulesSettingsFlappingProperties) {
+    setFlapping<State, Context, ActionGroupIds, RecoveryActionGroupId>(
+      flappingSettings,
+      this.processedAlerts.active,
+      this.processedAlerts.recovered
+    );
+  }
 }
diff --git a/x-pack/plugins/alerting/server/task_runner/task_runner.ts b/x-pack/plugins/alerting/server/task_runner/task_runner.ts
index a94512e1be4839..82e01a93125e58 100644
--- a/x-pack/plugins/alerting/server/task_runner/task_runner.ts
+++ b/x-pack/plugins/alerting/server/task_runner/task_runner.ts
@@ -466,6 +466,8 @@ export class TaskRunner<
       }
     });
 
+    this.legacyAlertsClient.setFlapping(flappingSettings);
+
     let alertsToReturn: Record<string, RawAlertInstance> = {};
     let recoveredAlertsToReturn: Record<string, RawAlertInstance> = {};
     // Only serialize alerts into task state if we're auto-recovering, otherwise