diff --git a/pkg/crd/testdata/cronjob_types.go b/pkg/crd/testdata/cronjob_types.go
index 42af267ab..d43622516 100644
--- a/pkg/crd/testdata/cronjob_types.go
+++ b/pkg/crd/testdata/cronjob_types.go
@@ -342,6 +342,13 @@ type CronJobSpec struct {
 	// +kubebuilder:validation:items:XIntOrString
 	// +kubebuilder:validation:items:Pattern="^((100|[0-9]{1,2})%|[0-9]+)$"
 	IntOrStringArrayWithAPattern []*intstr.IntOrString `json:"intOrStringArrayWithAPattern,omitempty"`
+
+	// This tests that we can embed protocol correctly (without ending up with allOf).
+	// Context: https://github.com/kubernetes-sigs/controller-tools/issues/1027
+	// Defaults to "TCP".
+	// +optional
+	// +default="TCP"
+	Protocol corev1.Protocol `json:"protocol,omitempty" protobuf:"bytes,4,opt,name=protocol,casttype=Protocol"`
 }
 
 type ContainsNestedMap struct {
diff --git a/pkg/crd/testdata/testdata.kubebuilder.io_cronjobs.yaml b/pkg/crd/testdata/testdata.kubebuilder.io_cronjobs.yaml
index a041e99f5..189f407a7 100644
--- a/pkg/crd/testdata/testdata.kubebuilder.io_cronjobs.yaml
+++ b/pkg/crd/testdata/testdata.kubebuilder.io_cronjobs.yaml
@@ -8949,6 +8949,13 @@ spec:
                 description: This tests that pattern validator is properly applied.
                 pattern: ^$|^((https):\/\/?)[^\s()<>]+(?:\([\w\d]+\)|([^[:punct:]\s]|\/?))$
                 type: string
+              protocol:
+                default: TCP
+                description: |-
+                  This tests that we can embed protocol correctly (without ending up with allOf).
+                  Context: https://github.com/kubernetes-sigs/controller-tools/issues/1027
+                  Defaults to "TCP".
+                type: string
               ptrData:
                 additionalProperties:
                   type: string