diff --git a/pkg/controller/instanceset/instance_util.go b/pkg/controller/instanceset/instance_util.go
index 5276b2b8a30..92f7ecb108b 100644
--- a/pkg/controller/instanceset/instance_util.go
+++ b/pkg/controller/instanceset/instance_util.go
@@ -434,7 +434,7 @@ func validateSpec(its *workloads.InstanceSet, tree *kubebuilderx.ObjectTree) err
 		replicasInTemplates += replicas
 		if templateNames.Has(template.Name) {
 			err = fmt.Errorf("duplicate instance template name: %s", template.Name)
-			if tree.EventRecorder != nil {
+			if tree != nil {
 				tree.EventRecorder.Event(its, corev1.EventTypeWarning, EventReasonInvalidSpec, err.Error())
 			}
 			return err
@@ -444,7 +444,7 @@ func validateSpec(its *workloads.InstanceSet, tree *kubebuilderx.ObjectTree) err
 	// sum of spec.templates[*].replicas should not greater than spec.replicas
 	if replicasInTemplates > *its.Spec.Replicas {
 		err = fmt.Errorf("total replicas in instances(%d) should not greater than replicas in spec(%d)", replicasInTemplates, *its.Spec.Replicas)
-		if tree.EventRecorder != nil {
+		if tree != nil {
 			tree.EventRecorder.Event(its, corev1.EventTypeWarning, EventReasonInvalidSpec, err.Error())
 		}
 		return err