diff --git a/control-plane/pkg/core/config/utils.go b/control-plane/pkg/core/config/utils.go
index 736264c5ad..4711857ef9 100644
--- a/control-plane/pkg/core/config/utils.go
+++ b/control-plane/pkg/core/config/utils.go
@@ -62,6 +62,10 @@ func EgressConfigFromDelivery(
 	egressConfig := &contract.EgressConfig{}
 
 	if delivery.DeadLetterSink != nil {
+		destination := *delivery.DeadLetterSink // Do not update object Spec, so copy destination.
+		if destination.Ref != nil && destination.Ref.Namespace == "" {
+			destination.Ref.Namespace = parent.GetNamespace()
+		}
 		deadLetterSinkURL, err := resolver.URIFromDestinationV1(ctx, *delivery.DeadLetterSink, parent)
 		if err != nil {
 			return nil, fmt.Errorf("failed to resolve Spec.Delivery.DeadLetterSink: %w", err)
diff --git a/control-plane/pkg/reconciler/broker/broker_test.go b/control-plane/pkg/reconciler/broker/broker_test.go
index c14aabf0e8..5de3214035 100644
--- a/control-plane/pkg/reconciler/broker/broker_test.go
+++ b/control-plane/pkg/reconciler/broker/broker_test.go
@@ -217,6 +217,63 @@ func brokerReconciliation(t *testing.T, format string, configs Configs) {
 				BootstrapServersConfigMapKey: bootstrapServers,
 			},
 		},
+		{
+			Name: "Reconciled normal - with DLS - no DLS ref namespace",
+			Objects: []runtime.Object{
+				NewBroker(
+					WithDelivery(WithNoDeadLetterSinkNamespace),
+				),
+				NewConfigMapFromContract(&contract.Contract{
+					Generation: 1,
+				}, &configs),
+				NewService(WithServiceNamespace(BrokerNamespace)),
+				BrokerReceiverPod(configs.SystemNamespace, map[string]string{base.VolumeGenerationAnnotationKey: "3"}),
+				BrokerDispatcherPod(configs.SystemNamespace, map[string]string{base.VolumeGenerationAnnotationKey: "1"}),
+			},
+			Key: testKey,
+			WantEvents: []string{
+				finalizerUpdatedEvent,
+			},
+			WantUpdates: []clientgotesting.UpdateActionImpl{
+				ConfigMapUpdate(&configs, &contract.Contract{
+					Resources: []*contract.Resource{
+						{
+							Uid:              BrokerUUID,
+							Topics:           []string{BrokerTopic()},
+							Ingress:          &contract.Ingress{ContentMode: contract.ContentMode_BINARY, IngressType: &contract.Ingress_Path{Path: receiver.Path(BrokerNamespace, BrokerName)}},
+							BootstrapServers: bootstrapServers,
+							EgressConfig:     &contract.EgressConfig{DeadLetter: ServiceURLFrom(BrokerNamespace, ServiceName)},
+						},
+					},
+					Generation: 2,
+				}),
+				BrokerReceiverPodUpdate(configs.SystemNamespace, map[string]string{
+					base.VolumeGenerationAnnotationKey: "2",
+				}),
+				BrokerDispatcherPodUpdate(configs.SystemNamespace, map[string]string{
+					base.VolumeGenerationAnnotationKey: "2",
+				}),
+			},
+			WantPatches: []clientgotesting.PatchActionImpl{
+				patchFinalizers(),
+			},
+			WantStatusUpdates: []clientgotesting.UpdateActionImpl{
+				{
+					Object: NewBroker(
+						WithDelivery(WithNoDeadLetterSinkNamespace),
+						reconcilertesting.WithInitBrokerConditions,
+						BrokerConfigMapUpdatedReady(&configs),
+						BrokerDataPlaneAvailable,
+						BrokerTopicReady,
+						BrokerConfigParsed,
+						BrokerAddressable(&configs),
+					),
+				},
+			},
+			OtherTestData: map[string]interface{}{
+				BootstrapServersConfigMapKey: bootstrapServers,
+			},
+		},
 		{
 			Name: "Failed to create topic",
 			Objects: []runtime.Object{
diff --git a/control-plane/pkg/reconciler/testing/objects_broker.go b/control-plane/pkg/reconciler/testing/objects_broker.go
index 610c81a4a5..b27705d2ca 100644
--- a/control-plane/pkg/reconciler/testing/objects_broker.go
+++ b/control-plane/pkg/reconciler/testing/objects_broker.go
@@ -77,7 +77,7 @@ func NewDeletedBroker(options ...reconcilertesting.BrokerOption) runtime.Object
 	)
 }
 
-func WithDelivery() func(*eventing.Broker) {
+func WithDelivery(mutations ...func(spec *eventingduck.DeliverySpec)) func(*eventing.Broker) {
 	service := NewService()
 
 	return func(broker *eventing.Broker) {
@@ -92,6 +92,15 @@ func WithDelivery() func(*eventing.Broker) {
 				APIVersion: service.APIVersion,
 			},
 		}
+		for _, mut := range mutations {
+			mut(broker.Spec.Delivery)
+		}
+	}
+}
+
+func WithNoDeadLetterSinkNamespace(spec *eventingduck.DeliverySpec) {
+	if spec.DeadLetterSink != nil && spec.DeadLetterSink.Ref != nil {
+		spec.DeadLetterSink.Ref.Namespace = ""
 	}
 }
 
diff --git a/control-plane/pkg/reconciler/testing/objects_common.go b/control-plane/pkg/reconciler/testing/objects_common.go
index e279298fc0..5268ca1dd4 100644
--- a/control-plane/pkg/reconciler/testing/objects_common.go
+++ b/control-plane/pkg/reconciler/testing/objects_common.go
@@ -17,6 +17,7 @@
 package testing
 
 import (
+	"fmt"
 	"io/ioutil"
 
 	"knative.dev/eventing-kafka-broker/control-plane/pkg/contract"
@@ -39,9 +40,8 @@ const (
 	ConfigMapNamespace = "test-namespace-config-map"
 	ConfigMapName      = "test-config-cm"
 
-	serviceNamespace = "test-service-namespace"
-	serviceName      = "test-service"
-	ServiceURL       = "http://test-service.test-service-namespace.svc.cluster.local"
+	ServiceNamespace = "test-service-namespace"
+	ServiceName      = "test-service"
 
 	TriggerUUID = "e7185016-5d98-4b54-84e8-3b1cd4acc6b5"
 
@@ -51,19 +51,35 @@ const (
 
 var (
 	Formats = []string{base.Protobuf, base.Json}
+
+	ServiceURL = ServiceURLFrom(ServiceNamespace, ServiceName)
 )
 
-func NewService() *corev1.Service {
-	return &corev1.Service{
+func NewService(mutations ...func(*corev1.Service)) *corev1.Service {
+	s := &corev1.Service{
 		TypeMeta: metav1.TypeMeta{
 			Kind:       "Service",
 			APIVersion: "v1",
 		},
 		ObjectMeta: metav1.ObjectMeta{
-			Name:      serviceName,
-			Namespace: serviceNamespace,
+			Name:      ServiceName,
+			Namespace: ServiceNamespace,
 		},
 	}
+	for _, mut := range mutations {
+		mut(s)
+	}
+	return s
+}
+
+func WithServiceNamespace(ns string) func(s *corev1.Service) {
+	return func(s *corev1.Service) {
+		s.Namespace = ns
+	}
+}
+
+func ServiceURLFrom(ns, name string) string {
+	return fmt.Sprintf("http://%s.%s.svc.cluster.local", name, ns)
 }
 
 func NewConfigMap(configs *Configs, data []byte) runtime.Object {