diff --git a/pkg/kubectl/scale_test.go b/pkg/kubectl/scale_test.go
index 96250d8fe1..f4e7a3b275 100644
--- a/pkg/kubectl/scale_test.go
+++ b/pkg/kubectl/scale_test.go
@@ -1049,3 +1049,264 @@ func TestValidateStatefulSet(t *testing.T) {
 		}
 	}
 }
+
+type ErrorReplicaSets struct {
+	extensionsclient.ReplicaSetInterface
+	conflict bool
+	invalid  bool
+}
+
+func (c *ErrorReplicaSets) Update(replicaSets *extensions.ReplicaSet) (*extensions.ReplicaSet, error) {
+	switch {
+	case c.invalid:
+		return nil, kerrors.NewInvalid(api.Kind(replicaSets.Kind), replicaSets.Name, nil)
+	case c.conflict:
+		return nil, kerrors.NewConflict(api.Resource(replicaSets.Kind), replicaSets.Name, nil)
+	}
+	return nil, errors.New("replicaSets update failure")
+}
+
+func (c *ErrorReplicaSets) Get(name string, options metav1.GetOptions) (*extensions.ReplicaSet, error) {
+	return &extensions.ReplicaSet{
+		Spec: extensions.ReplicaSetSpec{
+			Replicas: 0,
+		},
+	}, nil
+}
+
+type ErrorReplicaSetClient struct {
+	extensionsclient.ReplicaSetsGetter
+	conflict bool
+	invalid  bool
+}
+
+func (c *ErrorReplicaSetClient) ReplicaSets(namespace string) extensionsclient.ReplicaSetInterface {
+	return &ErrorReplicaSets{
+		ReplicaSetInterface: c.ReplicaSetsGetter.ReplicaSets(namespace),
+		invalid:             c.invalid,
+		conflict:            c.conflict,
+	}
+}
+
+func replicaSet() *extensions.ReplicaSet {
+	return &extensions.ReplicaSet{
+		ObjectMeta: metav1.ObjectMeta{
+			Namespace: metav1.NamespaceDefault,
+			Name:      "foo",
+		},
+	}
+}
+
+func TestReplicaSetScale(t *testing.T) {
+	fake := fake.NewSimpleClientset(replicaSet())
+	scaler := ReplicaSetScaler{fake.Extensions()}
+	preconditions := ScalePrecondition{-1, ""}
+	count := uint(3)
+	name := "foo"
+	scaler.Scale("default", name, count, &preconditions, nil, nil)
+
+	actions := fake.Actions()
+	if len(actions) != 2 {
+		t.Errorf("unexpected actions: %v, expected 2 actions (get, update)", actions)
+	}
+	if action, ok := actions[0].(testcore.GetAction); !ok || action.GetResource().GroupResource() != extensions.Resource("replicasets") || action.GetName() != name {
+		t.Errorf("unexpected action: %v, expected get-replicationSet %s", actions[0], name)
+	}
+	if action, ok := actions[1].(testcore.UpdateAction); !ok || action.GetResource().GroupResource() != extensions.Resource("replicasets") || action.GetObject().(*extensions.ReplicaSet).Spec.Replicas != int32(count) {
+		t.Errorf("unexpected action %v, expected update-replicaSet with replicas = %d", actions[1], count)
+	}
+}
+
+func TestReplicaSetScaleRetry(t *testing.T) {
+	fake := &ErrorReplicaSetClient{ReplicaSetsGetter: fake.NewSimpleClientset().Extensions(), conflict: true}
+	scaler := &ReplicaSetScaler{fake}
+	preconditions := &ScalePrecondition{-1, ""}
+	count := uint(3)
+	name := "foo"
+	namespace := "default"
+
+	scaleFunc := ScaleCondition(scaler, preconditions, namespace, name, count, nil)
+	pass, err := scaleFunc()
+	if pass != false {
+		t.Errorf("Expected an update failure to return pass = false, got pass = %v", pass)
+	}
+	if err != nil {
+		t.Errorf("Did not expect an error on update failure, got %v", err)
+	}
+	preconditions = &ScalePrecondition{3, ""}
+	scaleFunc = ScaleCondition(scaler, preconditions, namespace, name, count, nil)
+	pass, err = scaleFunc()
+	if err == nil {
+		t.Error("Expected error on precondition failure")
+	}
+}
+
+func TestReplicaSetScaleInvalid(t *testing.T) {
+	fake := &ErrorReplicaSetClient{ReplicaSetsGetter: fake.NewSimpleClientset().Extensions(), invalid: true}
+	scaler := ReplicaSetScaler{fake}
+	preconditions := ScalePrecondition{-1, ""}
+	count := uint(3)
+	name := "foo"
+	namespace := "default"
+
+	scaleFunc := ScaleCondition(&scaler, &preconditions, namespace, name, count, nil)
+	pass, err := scaleFunc()
+	if pass {
+		t.Errorf("Expected an update failure to return pass = false, got pass = %v", pass)
+	}
+	e, ok := err.(ScaleError)
+	if err == nil || !ok || e.FailureType != ScaleUpdateFailure {
+		t.Errorf("Expected error on invalid update failure, got %v", err)
+	}
+}
+
+func TestReplicaSetsGetterFailsPreconditions(t *testing.T) {
+	fake := fake.NewSimpleClientset(&extensions.ReplicaSet{
+		ObjectMeta: metav1.ObjectMeta{
+			Namespace: metav1.NamespaceDefault,
+			Name:      "foo",
+		},
+		Spec: extensions.ReplicaSetSpec{
+			Replicas: 10,
+		},
+	})
+	scaler := ReplicaSetScaler{fake.Extensions()}
+	preconditions := ScalePrecondition{2, ""}
+	count := uint(3)
+	name := "foo"
+	scaler.Scale("default", name, count, &preconditions, nil, nil)
+
+	actions := fake.Actions()
+	if len(actions) != 1 {
+		t.Errorf("unexpected actions: %v, expected 1 actions (get)", actions)
+	}
+	if action, ok := actions[0].(testcore.GetAction); !ok || action.GetResource().GroupResource() != extensions.Resource("replicasets") || action.GetName() != name {
+		t.Errorf("unexpected action: %v, expected get-replicaSets %s", actions[0], name)
+	}
+}
+
+func TestValidateReplicaSets(t *testing.T) {
+	zero, ten, twenty := int32(0), int32(10), int32(20)
+	tests := []struct {
+		preconditions ScalePrecondition
+		replicaSets   extensions.ReplicaSet
+		expectError   bool
+		test          string
+	}{
+		{
+			preconditions: ScalePrecondition{-1, ""},
+			expectError:   false,
+			test:          "defaults",
+		},
+		{
+			preconditions: ScalePrecondition{-1, ""},
+			replicaSets: extensions.ReplicaSet{
+				ObjectMeta: metav1.ObjectMeta{
+					ResourceVersion: "foo",
+				},
+				Spec: extensions.ReplicaSetSpec{
+					Replicas: ten,
+				},
+			},
+			expectError: false,
+			test:        "defaults 2",
+		},
+		{
+			preconditions: ScalePrecondition{0, ""},
+			replicaSets: extensions.ReplicaSet{
+				ObjectMeta: metav1.ObjectMeta{
+					ResourceVersion: "foo",
+				},
+				Spec: extensions.ReplicaSetSpec{
+					Replicas: zero,
+				},
+			},
+			expectError: false,
+			test:        "size matches",
+		},
+		{
+			preconditions: ScalePrecondition{-1, "foo"},
+			replicaSets: extensions.ReplicaSet{
+				ObjectMeta: metav1.ObjectMeta{
+					ResourceVersion: "foo",
+				},
+				Spec: extensions.ReplicaSetSpec{
+					Replicas: ten,
+				},
+			},
+			expectError: false,
+			test:        "resource version matches",
+		},
+		{
+			preconditions: ScalePrecondition{10, "foo"},
+			replicaSets: extensions.ReplicaSet{
+				ObjectMeta: metav1.ObjectMeta{
+					ResourceVersion: "foo",
+				},
+				Spec: extensions.ReplicaSetSpec{
+					Replicas: ten,
+				},
+			},
+			expectError: false,
+			test:        "both match",
+		},
+		{
+			preconditions: ScalePrecondition{10, "foo"},
+			replicaSets: extensions.ReplicaSet{
+				ObjectMeta: metav1.ObjectMeta{
+					ResourceVersion: "foo",
+				},
+				Spec: extensions.ReplicaSetSpec{
+					Replicas: twenty,
+				},
+			},
+			expectError: true,
+			test:        "size different",
+		},
+		{
+			preconditions: ScalePrecondition{10, "foo"},
+			replicaSets: extensions.ReplicaSet{
+				ObjectMeta: metav1.ObjectMeta{
+					ResourceVersion: "foo",
+				},
+			},
+			expectError: true,
+			test:        "no replicas",
+		},
+		{
+			preconditions: ScalePrecondition{10, "foo"},
+			replicaSets: extensions.ReplicaSet{
+				ObjectMeta: metav1.ObjectMeta{
+					ResourceVersion: "bar",
+				},
+				Spec: extensions.ReplicaSetSpec{
+					Replicas: ten,
+				},
+			},
+			expectError: true,
+			test:        "version different",
+		},
+		{
+			preconditions: ScalePrecondition{10, "foo"},
+			replicaSets: extensions.ReplicaSet{
+				ObjectMeta: metav1.ObjectMeta{
+					ResourceVersion: "bar",
+				},
+				Spec: extensions.ReplicaSetSpec{
+					Replicas: twenty,
+				},
+			},
+			expectError: true,
+			test:        "both different",
+		},
+	}
+	for _, test := range tests {
+		err := test.preconditions.ValidateReplicaSet(&test.replicaSets)
+		if err != nil && !test.expectError {
+			t.Errorf("unexpected error: %v (%s)", err, test.test)
+		}
+		if err == nil && test.expectError {
+			t.Errorf("expected an error: %v (%s)", err, test.test)
+		}
+	}
+}