diff --git a/pkg/reconciler/eventlistener/eventlistener.go b/pkg/reconciler/eventlistener/eventlistener.go
index 766dc9130..aade03652 100644
--- a/pkg/reconciler/eventlistener/eventlistener.go
+++ b/pkg/reconciler/eventlistener/eventlistener.go
@@ -354,15 +354,19 @@ func (r *Reconciler) reconcileCustomObject(ctx context.Context, el *v1beta1.Even
 			}
 		}
 
+		// Preserve any externally added annotations
+		data.SetAnnotations(kmeta.UnionMaps(data.GetAnnotations(), existingCustomObject.GetAnnotations()))
+
 		if !equality.Semantic.DeepEqual(data.GetLabels(), existingCustomObject.GetLabels()) ||
 			!equality.Semantic.DeepEqual(data.GetAnnotations(), existingCustomObject.GetAnnotations()) ||
 			!equality.Semantic.DeepEqual(data.Object["spec"], existingCustomObject.Object["spec"]) {
-			data = data.DeepCopy()
-			data.SetLabels(existingCustomObject.GetLabels())
-			data.SetAnnotations(existingCustomObject.GetAnnotations())
-			data.Object["spec"] = existingCustomObject.Object["spec"]
+			// Don't modify informer copy
+			existingCustomObject = existingCustomObject.DeepCopy()
+			existingCustomObject.SetLabels(data.GetLabels())
+			existingCustomObject.SetAnnotations(data.GetAnnotations())
+			existingCustomObject.Object["spec"] = data.Object["spec"]
 
-			if updated, err := r.DynamicClientSet.Resource(gvr).Namespace(data.GetNamespace()).Update(ctx, data, metav1.UpdateOptions{}); err != nil {
+			if updated, err := r.DynamicClientSet.Resource(gvr).Namespace(data.GetNamespace()).Update(ctx, existingCustomObject, metav1.UpdateOptions{}); err != nil {
 				logging.FromContext(ctx).Errorf("error updating to eventListener custom object: %v", err)
 				return err
 			} else if data.GetResourceVersion() != updated.GetResourceVersion() {
diff --git a/pkg/reconciler/eventlistener/eventlistener_test.go b/pkg/reconciler/eventlistener/eventlistener_test.go
index 258c7b39e..1ef54101b 100644
--- a/pkg/reconciler/eventlistener/eventlistener_test.go
+++ b/pkg/reconciler/eventlistener/eventlistener_test.go
@@ -400,7 +400,8 @@ func makeWithPod(ops ...func(d *duckv1.WithPod)) *duckv1.WithPod {
 			OwnerReferences: []metav1.OwnerReference{
 				*ownerRefs,
 			},
-			Labels: generatedLabels,
+			Annotations: map[string]string{},
+			Labels:      generatedLabels,
 		},
 		Spec: duckv1.WithPodSpec{
 			Template: duckv1.PodSpecable{
@@ -1379,6 +1380,7 @@ func TestReconcile(t *testing.T) {
 			Namespaces:     []*corev1.Namespace{namespaceResource},
 			EventListeners: []*v1beta1.EventListener{elWithCustomResourceForEnv},
 			ConfigMaps:     []*corev1.ConfigMap{loggingConfigMap, observabilityConfigMap},
+			WithPod:        []*duckv1.WithPod{envForCustomResource},
 		},
 		endResources: test.Resources{
 			Namespaces:     []*corev1.Namespace{namespaceResource},
@@ -1408,6 +1410,7 @@ func TestReconcile(t *testing.T) {
 			Namespaces:     []*corev1.Namespace{namespaceResource},
 			EventListeners: []*v1beta1.EventListener{elWithCustomResourceForArgs},
 			ConfigMaps:     []*corev1.ConfigMap{loggingConfigMap, observabilityConfigMap},
+			WithPod:        []*duckv1.WithPod{argsForCustomResource},
 		},
 		endResources: test.Resources{
 			Namespaces:     []*corev1.Namespace{namespaceResource},
@@ -1422,6 +1425,7 @@ func TestReconcile(t *testing.T) {
 			Namespaces:     []*corev1.Namespace{namespaceResource},
 			EventListeners: []*v1beta1.EventListener{elWithCustomResourceForImage},
 			ConfigMaps:     []*corev1.ConfigMap{loggingConfigMap, observabilityConfigMap},
+			WithPod:        []*duckv1.WithPod{imageForCustomResource},
 		},
 		endResources: test.Resources{
 			Namespaces:     []*corev1.Namespace{namespaceResource},