diff --git a/pkg/webhook/admission/defaulter_custom.go b/pkg/webhook/admission/defaulter_custom.go
index d65727e62c..7007984245 100644
--- a/pkg/webhook/admission/defaulter_custom.go
+++ b/pkg/webhook/admission/defaulter_custom.go
@@ -22,7 +22,9 @@ import (
 	"errors"
 	"net/http"
 
+	admissionv1 "k8s.io/api/admission/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 )
 
@@ -60,6 +62,16 @@ func (h *defaulterForType) Handle(ctx context.Context, req Request) Response {
 		panic("object should never be nil")
 	}
 
+	// Always skip when a DELETE operation received in custom mutation handler.
+	if req.Operation == admissionv1.Delete {
+		return Response{AdmissionResponse: admissionv1.AdmissionResponse{
+			Allowed: true,
+			Result: &metav1.Status{
+				Code: http.StatusOK,
+			},
+		}}
+	}
+
 	ctx = NewContextWithRequest(ctx, req)
 
 	// Get the object in the request