diff --git a/controllers/actions.summerwind.net/horizontal_runner_autoscaler_webhook.go b/controllers/actions.summerwind.net/horizontal_runner_autoscaler_webhook.go
index e3710924d2..5f1f15007c 100644
--- a/controllers/actions.summerwind.net/horizontal_runner_autoscaler_webhook.go
+++ b/controllers/actions.summerwind.net/horizontal_runner_autoscaler_webhook.go
@@ -681,78 +681,80 @@ func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) SetupWithManager(mgr
 
 	autoscaler.Recorder = mgr.GetEventRecorderFor(name)
 
-	if err := mgr.GetFieldIndexer().IndexField(context.TODO(), &v1alpha1.HorizontalRunnerAutoscaler{}, scaleTargetKey, func(rawObj client.Object) []string {
-		hra := rawObj.(*v1alpha1.HorizontalRunnerAutoscaler)
+	if err := mgr.GetFieldIndexer().IndexField(context.TODO(), &v1alpha1.HorizontalRunnerAutoscaler{}, scaleTargetKey, autoscaler.indexer); err != nil {
+		return err
+	}
+
+	return ctrl.NewControllerManagedBy(mgr).
+		For(&v1alpha1.HorizontalRunnerAutoscaler{}).
+		Named(name).
+		Complete(autoscaler)
+}
+
+func (autoscaler *HorizontalRunnerAutoscalerGitHubWebhook) indexer(rawObj client.Object) []string {
+	hra := rawObj.(*v1alpha1.HorizontalRunnerAutoscaler)
+
+	if hra.Spec.ScaleTargetRef.Name == "" {
+		autoscaler.Log.V(1).Info(fmt.Sprintf("scale target ref name not set for hra %s", hra.Name))
+		return nil
+	}
 
-		if hra.Spec.ScaleTargetRef.Name == "" {
-			autoscaler.Log.V(1).Info(fmt.Sprintf("scale target ref name not set for hra %s", hra.Name))
+	switch hra.Spec.ScaleTargetRef.Kind {
+	case "", "RunnerDeployment":
+		var rd v1alpha1.RunnerDeployment
+		if err := autoscaler.Client.Get(context.Background(), types.NamespacedName{Namespace: hra.Namespace, Name: hra.Spec.ScaleTargetRef.Name}, &rd); err != nil {
+			autoscaler.Log.V(1).Info(fmt.Sprintf("RunnerDeployment not found with scale target ref name %s for hra %s", hra.Spec.ScaleTargetRef.Name, hra.Name))
 			return nil
 		}
 
-		switch hra.Spec.ScaleTargetRef.Kind {
-		case "", "RunnerDeployment":
-			var rd v1alpha1.RunnerDeployment
-			if err := autoscaler.Client.Get(context.Background(), types.NamespacedName{Namespace: hra.Namespace, Name: hra.Spec.ScaleTargetRef.Name}, &rd); err != nil {
-				autoscaler.Log.V(1).Info(fmt.Sprintf("RunnerDeployment not found with scale target ref name %s for hra %s", hra.Spec.ScaleTargetRef.Name, hra.Name))
-				return nil
-			}
-
-			keys := []string{}
-			if rd.Spec.Template.Spec.Repository != "" {
-				keys = append(keys, rd.Spec.Template.Spec.Repository) // Repository runners
-			}
-			if rd.Spec.Template.Spec.Organization != "" {
-				if group := rd.Spec.Template.Spec.Group; group != "" {
-					keys = append(keys, organizationalRunnerGroupKey(rd.Spec.Template.Spec.Organization, rd.Spec.Template.Spec.Group)) // Organization runner groups
-				} else {
-					keys = append(keys, rd.Spec.Template.Spec.Organization) // Organization runners
-				}
-			}
-			if enterprise := rd.Spec.Template.Spec.Enterprise; enterprise != "" {
-				if group := rd.Spec.Template.Spec.Group; group != "" {
-					keys = append(keys, enterpriseRunnerGroupKey(enterprise, rd.Spec.Template.Spec.Group)) // Enterprise runner groups
-				} else {
-					keys = append(keys, enterpriseKey(enterprise)) // Enterprise runners
-				}
+		keys := []string{}
+		if rd.Spec.Template.Spec.Repository != "" {
+			keys = append(keys, rd.Spec.Template.Spec.Repository) // Repository runners
+		}
+		if rd.Spec.Template.Spec.Organization != "" {
+			if group := rd.Spec.Template.Spec.Group; group != "" {
+				keys = append(keys, organizationalRunnerGroupKey(rd.Spec.Template.Spec.Organization, rd.Spec.Template.Spec.Group)) // Organization runner groups
+			} else {
+				keys = append(keys, rd.Spec.Template.Spec.Organization) // Organization runners
 			}
-			autoscaler.Log.V(2).Info(fmt.Sprintf("HRA keys indexed for HRA %s: %v", hra.Name, keys))
-			return keys
-		case "RunnerSet":
-			var rs v1alpha1.RunnerSet
-			if err := autoscaler.Client.Get(context.Background(), types.NamespacedName{Namespace: hra.Namespace, Name: hra.Spec.ScaleTargetRef.Name}, &rs); err != nil {
-				autoscaler.Log.V(1).Info(fmt.Sprintf("RunnerSet not found with scale target ref name %s for hra %s", hra.Spec.ScaleTargetRef.Name, hra.Name))
-				return nil
+		}
+		if enterprise := rd.Spec.Template.Spec.Enterprise; enterprise != "" {
+			if group := rd.Spec.Template.Spec.Group; group != "" {
+				keys = append(keys, enterpriseRunnerGroupKey(enterprise, rd.Spec.Template.Spec.Group)) // Enterprise runner groups
+			} else {
+				keys = append(keys, enterpriseKey(enterprise)) // Enterprise runners
 			}
+		}
+		autoscaler.Log.V(2).Info(fmt.Sprintf("HRA keys indexed for HRA %s: %v", hra.Name, keys))
+		return keys
+	case "RunnerSet":
+		var rs v1alpha1.RunnerSet
+		if err := autoscaler.Client.Get(context.Background(), types.NamespacedName{Namespace: hra.Namespace, Name: hra.Spec.ScaleTargetRef.Name}, &rs); err != nil {
+			autoscaler.Log.V(1).Info(fmt.Sprintf("RunnerSet not found with scale target ref name %s for hra %s", hra.Spec.ScaleTargetRef.Name, hra.Name))
+			return nil
+		}
 
-			keys := []string{}
-			if rs.Spec.Repository != "" {
-				keys = append(keys, rs.Spec.Repository) // Repository runners
-			}
-			if rs.Spec.Organization != "" {
-				keys = append(keys, rs.Spec.Organization) // Organization runners
-				if group := rs.Spec.Group; group != "" {
-					keys = append(keys, organizationalRunnerGroupKey(rs.Spec.Organization, rs.Spec.Group)) // Organization runner groups
-				}
+		keys := []string{}
+		if rs.Spec.Repository != "" {
+			keys = append(keys, rs.Spec.Repository) // Repository runners
+		}
+		if rs.Spec.Organization != "" {
+			keys = append(keys, rs.Spec.Organization) // Organization runners
+			if group := rs.Spec.Group; group != "" {
+				keys = append(keys, organizationalRunnerGroupKey(rs.Spec.Organization, rs.Spec.Group)) // Organization runner groups
 			}
-			if enterprise := rs.Spec.Enterprise; enterprise != "" {
-				keys = append(keys, enterpriseKey(enterprise)) // Enterprise runners
-				if group := rs.Spec.Group; group != "" {
-					keys = append(keys, enterpriseRunnerGroupKey(enterprise, rs.Spec.Group)) // Enterprise runner groups
-				}
+		}
+		if enterprise := rs.Spec.Enterprise; enterprise != "" {
+			keys = append(keys, enterpriseKey(enterprise)) // Enterprise runners
+			if group := rs.Spec.Group; group != "" {
+				keys = append(keys, enterpriseRunnerGroupKey(enterprise, rs.Spec.Group)) // Enterprise runner groups
 			}
-			autoscaler.Log.V(2).Info(fmt.Sprintf("HRA keys indexed for HRA %s: %v", hra.Name, keys))
-			return keys
 		}
-
-		return nil
-	}); err != nil {
-		return err
+		autoscaler.Log.V(2).Info(fmt.Sprintf("HRA keys indexed for HRA %s: %v", hra.Name, keys))
+		return keys
 	}
 
-	return ctrl.NewControllerManagedBy(mgr).
-		For(&v1alpha1.HorizontalRunnerAutoscaler{}).
-		Named(name).
-		Complete(autoscaler)
+	return nil
 }
 
 func enterpriseKey(name string) string {
diff --git a/controllers/actions.summerwind.net/horizontal_runner_autoscaler_webhook_test.go b/controllers/actions.summerwind.net/horizontal_runner_autoscaler_webhook_test.go
index 1675b88be4..20f81f17f2 100644
--- a/controllers/actions.summerwind.net/horizontal_runner_autoscaler_webhook_test.go
+++ b/controllers/actions.summerwind.net/horizontal_runner_autoscaler_webhook_test.go
@@ -431,7 +431,11 @@ func testServerWithInitObjs(t *testing.T, eventType string, event interface{}, w
 
 	hraWebhook := &HorizontalRunnerAutoscalerGitHubWebhook{}
 
-	client := fake.NewClientBuilder().WithScheme(sc).WithRuntimeObjects(initObjs...).Build()
+	client := fake.NewClientBuilder().
+		WithScheme(sc).
+		WithRuntimeObjects(initObjs...).
+		WithIndex(&actionsv1alpha1.HorizontalRunnerAutoscaler{}, scaleTargetKey, hraWebhook.indexer).
+		Build()
 
 	logs := installTestLogger(hraWebhook)