diff --git a/pkg/client/testing/core/fake_test.go b/pkg/client/testing/core/fake_test.go
index 78f0286df3b..d8b65897cf7 100644
--- a/pkg/client/testing/core/fake_test.go
+++ b/pkg/client/testing/core/fake_test.go
@@ -94,6 +94,65 @@ func TestFakeClientSetFiltering(t *testing.T) {
 	}
 }
 
+func TestFakeClientsetInheritsNamespace(t *testing.T) {
+	tc := clientsetfake.NewSimpleClientset(
+		testNamespace("nsA"),
+		testPod("nsA", "pod-1"),
+	)
+
+	_, err := tc.Core().Namespaces().Create(testNamespace("nsB"))
+	if err != nil {
+		t.Fatalf("Namespaces.Create: %s", err)
+	}
+
+	allNS, err := tc.Core().Namespaces().List(api.ListOptions{})
+	if err != nil {
+		t.Fatalf("Namespaces.List: %s", err)
+	}
+	if actual, expected := len(allNS.Items), 2; expected != actual {
+		t.Fatalf("Expected %d namespaces to match, got %d", expected, actual)
+	}
+
+	_, err = tc.Core().Pods("nsB").Create(testPod("", "pod-1"))
+	if err != nil {
+		t.Fatalf("Pods.Create nsB/pod-1: %s", err)
+	}
+
+	podB1, err := tc.Core().Pods("nsB").Get("pod-1", metav1.GetOptions{})
+	if err != nil {
+		t.Fatalf("Pods.Get nsB/pod-1: %s", err)
+	}
+	if podB1 == nil {
+		t.Fatalf("Expected to find pod nsB/pod-1 but it wasn't found")
+	}
+	if podB1.Namespace != "nsB" || podB1.Name != "pod-1" {
+		t.Fatalf("Expected to find pod nsB/pod-1t, got %s/%s", podB1.Namespace, podB1.Name)
+	}
+
+	_, err = tc.Core().Pods("nsA").Create(testPod("", "pod-1"))
+	if err == nil {
+		t.Fatalf("Expected Pods.Create to fail with already exists error")
+	}
+
+	_, err = tc.Core().Pods("nsA").Update(testPod("", "pod-1"))
+	if err != nil {
+		t.Fatalf("Pods.Update nsA/pod-1: %s", err)
+	}
+
+	_, err = tc.Core().Pods("nsA").Create(testPod("nsB", "pod-2"))
+	if err == nil {
+		t.Fatalf("Expected Pods.Create to fail with bad request from namespace mismtach")
+	}
+	if err.Error() != `request namespace does not match object namespace, request: "nsA" object: "nsB"` {
+		t.Fatalf("Expected Pods.Create error to provide object and request namespaces, got %q", err)
+	}
+
+	_, err = tc.Core().Pods("nsA").Update(testPod("", "pod-3"))
+	if err == nil {
+		t.Fatalf("Expected Pods.Update nsA/pod-3 to fail with not found error")
+	}
+}
+
 func testSA(ns, name string) *api.ServiceAccount {
 	return &api.ServiceAccount{
 		ObjectMeta: api.ObjectMeta{
@@ -111,3 +170,11 @@ func testPod(ns, name string) *api.Pod {
 		},
 	}
 }
+
+func testNamespace(ns string) *api.Namespace {
+	return &api.Namespace{
+		ObjectMeta: api.ObjectMeta{
+			Name: ns,
+		},
+	}
+}
diff --git a/pkg/client/testing/core/fixture.go b/pkg/client/testing/core/fixture.go
index cdc00b5388f..585bba4f856 100644
--- a/pkg/client/testing/core/fixture.go
+++ b/pkg/client/testing/core/fixture.go
@@ -41,8 +41,11 @@ type ObjectTracker interface {
 	// Get retrieves the object by its kind, namespace and name.
 	Get(gvk schema.GroupVersionKind, ns, name string) (runtime.Object, error)
 
-	// Update updates an existing object in the tracker.
-	Update(obj runtime.Object) error
+	// Create adds an object to the tracker in the specified namespace.
+	Create(obj runtime.Object, ns string) error
+
+	// Update updates an existing object in the tracker in the specified namespace.
+	Update(obj runtime.Object, ns string) error
 
 	// List retrieves all objects of a given kind in the given
 	// namespace. Only non-List kinds are accepted.
@@ -102,12 +105,12 @@ func ObjectReaction(tracker ObjectTracker, mapper meta.RESTMapper) ReactionFunc
 				return true, nil, err
 			}
 			if action.GetSubresource() == "" {
-				err = tracker.Add(action.GetObject())
+				err = tracker.Create(action.GetObject(), ns)
 			} else {
 				// TODO: Currently we're handling subresource creation as an update
 				// on the enclosing resource. This works for some subresources but
 				// might not be generic enough.
-				err = tracker.Update(action.GetObject())
+				err = tracker.Update(action.GetObject(), ns)
 			}
 			if err != nil {
 				return true, nil, err
@@ -120,7 +123,7 @@ func ObjectReaction(tracker ObjectTracker, mapper meta.RESTMapper) ReactionFunc
 			if err != nil {
 				return true, nil, err
 			}
-			err = tracker.Update(action.GetObject())
+			err = tracker.Update(action.GetObject(), ns)
 			if err != nil {
 				return true, nil, err
 			}
@@ -243,18 +246,26 @@ func (t *tracker) Get(gvk schema.GroupVersionKind, ns, name string) (runtime.Obj
 }
 
 func (t *tracker) Add(obj runtime.Object) error {
-	return t.add(obj, false)
-}
-
-func (t *tracker) Update(obj runtime.Object) error {
-	return t.add(obj, true)
-}
-
-func (t *tracker) add(obj runtime.Object, replaceExisting bool) error {
 	if meta.IsListType(obj) {
-		return t.addList(obj, replaceExisting)
+		return t.addList(obj, false)
 	}
 
+	objMeta, err := meta.Accessor(obj)
+	if err != nil {
+		return err
+	}
+	return t.add(obj, objMeta.GetNamespace(), false)
+}
+
+func (t *tracker) Create(obj runtime.Object, ns string) error {
+	return t.add(obj, ns, false)
+}
+
+func (t *tracker) Update(obj runtime.Object, ns string) error {
+	return t.add(obj, ns, true)
+}
+
+func (t *tracker) add(obj runtime.Object, ns string, replaceExisting bool) error {
 	gvks, _, err := t.scheme.ObjectKinds(obj)
 	if err != nil {
 		return err
@@ -286,6 +297,16 @@ func (t *tracker) add(obj runtime.Object, replaceExisting bool) error {
 			return err
 		}
 
+		// Propagate namespace to the new object if hasn't already been set.
+		if len(newMeta.GetNamespace()) == 0 {
+			newMeta.SetNamespace(ns)
+		}
+
+		if ns != newMeta.GetNamespace() {
+			msg := fmt.Sprintf("request namespace does not match object namespace, request: %q object: %q", ns, newMeta.GetNamespace())
+			return errors.NewBadRequest(msg)
+		}
+
 		if err := checkNamespace(gvk, newMeta.GetNamespace()); err != nil {
 			return err
 		}
@@ -325,7 +346,11 @@ func (t *tracker) addList(obj runtime.Object, replaceExisting bool) error {
 		return errs[0]
 	}
 	for _, obj := range list {
-		err := t.add(obj, replaceExisting)
+		objMeta, err := meta.Accessor(obj)
+		if err != nil {
+			return err
+		}
+		err = t.add(obj, objMeta.GetNamespace(), replaceExisting)
 		if err != nil {
 			return err
 		}