diff --git a/staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd_test.go b/staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd_test.go
index bbf5c9c742e..132b486d6eb 100644
--- a/staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd_test.go
+++ b/staging/src/k8s.io/apiextensions-apiserver/pkg/registry/customresource/etcd_test.go
@@ -17,6 +17,8 @@ limitations under the License.
 package customresource_test
 
 import (
+	"context"
+	"fmt"
 	"reflect"
 	"strings"
 	"testing"
@@ -526,6 +528,184 @@ func TestScaleUpdateWithoutSpecReplicas(t *testing.T) {
 	}
 }
 
+func TestScaleUpdateWithoutResourceVersion(t *testing.T) {
+	storage, server := newStorage(t)
+	defer server.Terminate(t)
+	defer storage.CustomResource.Store.DestroyFunc()
+
+	name := "foo"
+
+	var cr unstructured.Unstructured
+	ctx := genericapirequest.WithNamespace(genericapirequest.NewContext(), metav1.NamespaceDefault)
+	key := "/noxus/" + metav1.NamespaceDefault + "/" + name
+	if err := storage.CustomResource.Storage.Create(ctx, key, &validCustomResource, &cr, 0, false); err != nil {
+		t.Fatalf("error setting new custom resource (key: %s) %v: %v", key, validCustomResource, err)
+	}
+
+	replicas := int32(8)
+	update := autoscalingv1.Scale{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: name,
+		},
+		Spec: autoscalingv1.ScaleSpec{
+			Replicas: replicas,
+		},
+	}
+
+	if _, _, err := storage.Scale.Update(ctx, update.Name, rest.DefaultUpdatedObjectInfo(&update), rest.ValidateAllObjectFunc, rest.ValidateAllObjectUpdateFunc, false, &metav1.UpdateOptions{}); err != nil {
+		t.Fatalf("error updating scale %v: %v", update, err)
+	}
+
+	obj, err := storage.Scale.Get(ctx, name, &metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("error fetching scale for %s: %v", name, err)
+	}
+	scale := obj.(*autoscalingv1.Scale)
+	if scale.Spec.Replicas != replicas {
+		t.Errorf("wrong replicas count: expected: %d got: %d", replicas, scale.Spec.Replicas)
+	}
+}
+
+func TestScaleUpdateWithoutResourceVersionWithConflicts(t *testing.T) {
+	storage, server := newStorage(t)
+	defer server.Terminate(t)
+	defer storage.CustomResource.Store.DestroyFunc()
+
+	name := "foo"
+
+	var cr unstructured.Unstructured
+	ctx := genericapirequest.WithNamespace(genericapirequest.NewContext(), metav1.NamespaceDefault)
+	key := "/noxus/" + metav1.NamespaceDefault + "/" + name
+	if err := storage.CustomResource.Storage.Create(ctx, key, &validCustomResource, &cr, 0, false); err != nil {
+		t.Fatalf("error setting new custom resource (key: %s) %v: %v", key, validCustomResource, err)
+	}
+
+	fetchObject := func(name string) (*unstructured.Unstructured, error) {
+		gotObj, err := storage.CustomResource.Get(ctx, name, &metav1.GetOptions{})
+		if err != nil {
+			return nil, fmt.Errorf("error fetching custom resource %s: %v", name, err)
+		}
+		return gotObj.(*unstructured.Unstructured), nil
+	}
+
+	applyPatch := func(labelName, labelValue string) rest.TransformFunc {
+		return func(_ context.Context, _, currentObject runtime.Object) (objToUpdate runtime.Object, patchErr error) {
+			o := currentObject.(metav1.Object)
+			o.SetLabels(map[string]string{
+				labelName: labelValue,
+			})
+			return currentObject, nil
+		}
+	}
+
+	errs := make(chan error, 1)
+	rounds := 100
+	go func() {
+		// continuously submits a patch that updates a label and verifies the label update was effective
+		labelName := "timestamp"
+		for i := 0; i < rounds; i++ {
+			expectedLabelValue := fmt.Sprint(i)
+			update, err := fetchObject(name)
+			if err != nil {
+				errs <- err
+				return
+			}
+			setNestedField(update, expectedLabelValue, "metadata", "labels", labelName)
+			if _, _, err := storage.CustomResource.Update(ctx, name, rest.DefaultUpdatedObjectInfo(nil, applyPatch(labelName, fmt.Sprint(i))), rest.ValidateAllObjectFunc, rest.ValidateAllObjectUpdateFunc, false, &metav1.UpdateOptions{}); err != nil {
+
+				errs <- fmt.Errorf("error updating custom resource label: %v", err)
+				return
+			}
+
+			gotObj, err := fetchObject(name)
+			if err != nil {
+				errs <- err
+				return
+			}
+			gotLabelValue, _, err := unstructured.NestedString(gotObj.Object, "metadata", "labels", labelName)
+			if err != nil {
+				errs <- fmt.Errorf("error getting label %s of custom resource %s: %v", labelName, name, err)
+				return
+			}
+			if gotLabelValue != expectedLabelValue {
+				errs <- fmt.Errorf("wrong label value: expected: %s, got: %s", expectedLabelValue, gotLabelValue)
+				return
+			}
+		}
+	}()
+
+	replicas := int32(0)
+	update := autoscalingv1.Scale{
+		ObjectMeta: metav1.ObjectMeta{
+			Name: name,
+		},
+	}
+	// continuously submits a scale update without a resourceVersion for a monotonically increasing replica value
+	// and verifies the scale update was effective
+	for i := 0; i < rounds; i++ {
+		select {
+		case err := <-errs:
+			t.Fatal(err)
+		default:
+			replicas++
+			update.Spec.Replicas = replicas
+			if _, _, err := storage.Scale.Update(ctx, update.Name, rest.DefaultUpdatedObjectInfo(&update), rest.ValidateAllObjectFunc, rest.ValidateAllObjectUpdateFunc, false, &metav1.UpdateOptions{}); err != nil {
+				t.Fatalf("error updating scale %v: %v", update, err)
+			}
+
+			obj, err := storage.Scale.Get(ctx, name, &metav1.GetOptions{})
+			if err != nil {
+				t.Fatalf("error fetching scale for %s: %v", name, err)
+			}
+			scale := obj.(*autoscalingv1.Scale)
+			if scale.Spec.Replicas != replicas {
+				t.Errorf("wrong replicas count: expected: %d got: %d", replicas, scale.Spec.Replicas)
+			}
+		}
+	}
+}
+
+func TestScaleUpdateWithResourceVersionWithConflicts(t *testing.T) {
+	storage, server := newStorage(t)
+	defer server.Terminate(t)
+	defer storage.CustomResource.Store.DestroyFunc()
+
+	name := "foo"
+
+	var cr unstructured.Unstructured
+	ctx := genericapirequest.WithNamespace(genericapirequest.NewContext(), metav1.NamespaceDefault)
+	key := "/noxus/" + metav1.NamespaceDefault + "/" + name
+	if err := storage.CustomResource.Storage.Create(ctx, key, &validCustomResource, &cr, 0, false); err != nil {
+		t.Fatalf("error setting new custom resource (key: %s) %v: %v", key, validCustomResource, err)
+	}
+
+	obj, err := storage.Scale.Get(ctx, name, &metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("error fetching scale for %s: %v", name, err)
+	}
+	scale, ok := obj.(*autoscalingv1.Scale)
+	if !ok {
+		t.Fatalf("%v is not of the type autoscalingv1.Scale", scale)
+	}
+
+	replicas := int32(12)
+	update := autoscalingv1.Scale{
+		ObjectMeta: scale.ObjectMeta,
+		Spec: autoscalingv1.ScaleSpec{
+			Replicas: replicas,
+		},
+	}
+	update.ResourceVersion = "1"
+
+	_, _, err = storage.Scale.Update(ctx, update.Name, rest.DefaultUpdatedObjectInfo(&update), rest.ValidateAllObjectFunc, rest.ValidateAllObjectUpdateFunc, false, &metav1.UpdateOptions{})
+	if err == nil {
+		t.Fatal("expecting an update conflict error")
+	}
+	if !errors.IsConflict(err) {
+		t.Fatalf("unexpected error, expecting an update conflict but got %v", err)
+	}
+}
+
 func setSpecReplicas(u *unstructured.Unstructured, replicas int64) {
 	setNestedField(u, replicas, "spec", "replicas")
 }