diff --git a/pkg/api/defaulting_test.go b/pkg/api/defaulting_test.go
index bd1cc096a5..ab81d00b5b 100644
--- a/pkg/api/defaulting_test.go
+++ b/pkg/api/defaulting_test.go
@@ -53,44 +53,48 @@ func TestVerifyDefaulting(t *testing.T) {
 func TestDefaulting(t *testing.T) {
 	// these are the known types with defaulters - you must add to this list if you add a top level defaulter
 	typesWithDefaulting := map[unversioned.GroupVersionKind]struct{}{
-		{Group: "", Version: "v1", Kind: "ConfigMap"}:                                             {},
-		{Group: "", Version: "v1", Kind: "ConfigMapList"}:                                         {},
-		{Group: "", Version: "v1", Kind: "Endpoints"}:                                             {},
-		{Group: "", Version: "v1", Kind: "EndpointsList"}:                                         {},
-		{Group: "", Version: "v1", Kind: "Namespace"}:                                             {},
-		{Group: "", Version: "v1", Kind: "NamespaceList"}:                                         {},
-		{Group: "", Version: "v1", Kind: "Node"}:                                                  {},
-		{Group: "", Version: "v1", Kind: "NodeList"}:                                              {},
-		{Group: "", Version: "v1", Kind: "PersistentVolume"}:                                      {},
-		{Group: "", Version: "v1", Kind: "PersistentVolumeList"}:                                  {},
-		{Group: "", Version: "v1", Kind: "PersistentVolumeClaim"}:                                 {},
-		{Group: "", Version: "v1", Kind: "PersistentVolumeClaimList"}:                             {},
-		{Group: "", Version: "v1", Kind: "PodAttachOptions"}:                                      {},
-		{Group: "", Version: "v1", Kind: "PodExecOptions"}:                                        {},
-		{Group: "", Version: "v1", Kind: "Pod"}:                                                   {},
-		{Group: "", Version: "v1", Kind: "PodList"}:                                               {},
-		{Group: "", Version: "v1", Kind: "PodTemplate"}:                                           {},
-		{Group: "", Version: "v1", Kind: "PodTemplateList"}:                                       {},
-		{Group: "", Version: "v1", Kind: "ReplicationController"}:                                 {},
-		{Group: "", Version: "v1", Kind: "ReplicationControllerList"}:                             {},
-		{Group: "", Version: "v1", Kind: "Secret"}:                                                {},
-		{Group: "", Version: "v1", Kind: "SecretList"}:                                            {},
-		{Group: "", Version: "v1", Kind: "Service"}:                                               {},
-		{Group: "", Version: "v1", Kind: "ServiceList"}:                                           {},
-		{Group: "apps", Version: "v1alpha1", Kind: "StatefulSet"}:                                 {},
-		{Group: "apps", Version: "v1alpha1", Kind: "StatefulSetList"}:                             {},
-		{Group: "autoscaling", Version: "v1", Kind: "HorizontalPodAutoscaler"}:                    {},
-		{Group: "autoscaling", Version: "v1", Kind: "HorizontalPodAutoscalerList"}:                {},
-		{Group: "batch", Version: "v1", Kind: "Job"}:                                              {},
-		{Group: "batch", Version: "v1", Kind: "JobList"}:                                          {},
-		{Group: "batch", Version: "v2alpha1", Kind: "Job"}:                                        {},
-		{Group: "batch", Version: "v2alpha1", Kind: "JobList"}:                                    {},
-		{Group: "batch", Version: "v2alpha1", Kind: "JobTemplate"}:                                {},
-		{Group: "batch", Version: "v2alpha1", Kind: "ScheduledJob"}:                               {},
-		{Group: "batch", Version: "v2alpha1", Kind: "ScheduledJobList"}:                           {},
-		{Group: "componentconfig", Version: "v1alpha1", Kind: "KubeProxyConfiguration"}:           {},
-		{Group: "componentconfig", Version: "v1alpha1", Kind: "KubeSchedulerConfiguration"}:       {},
-		{Group: "componentconfig", Version: "v1alpha1", Kind: "KubeletConfiguration"}:             {},
+		{Group: "", Version: "v1", Kind: "ConfigMap"}:                                       {},
+		{Group: "", Version: "v1", Kind: "ConfigMapList"}:                                   {},
+		{Group: "", Version: "v1", Kind: "Endpoints"}:                                       {},
+		{Group: "", Version: "v1", Kind: "EndpointsList"}:                                   {},
+		{Group: "", Version: "v1", Kind: "Namespace"}:                                       {},
+		{Group: "", Version: "v1", Kind: "NamespaceList"}:                                   {},
+		{Group: "", Version: "v1", Kind: "Node"}:                                            {},
+		{Group: "", Version: "v1", Kind: "NodeList"}:                                        {},
+		{Group: "", Version: "v1", Kind: "PersistentVolume"}:                                {},
+		{Group: "", Version: "v1", Kind: "PersistentVolumeList"}:                            {},
+		{Group: "", Version: "v1", Kind: "PersistentVolumeClaim"}:                           {},
+		{Group: "", Version: "v1", Kind: "PersistentVolumeClaimList"}:                       {},
+		{Group: "", Version: "v1", Kind: "PodAttachOptions"}:                                {},
+		{Group: "", Version: "v1", Kind: "PodExecOptions"}:                                  {},
+		{Group: "", Version: "v1", Kind: "Pod"}:                                             {},
+		{Group: "", Version: "v1", Kind: "PodList"}:                                         {},
+		{Group: "", Version: "v1", Kind: "PodTemplate"}:                                     {},
+		{Group: "", Version: "v1", Kind: "PodTemplateList"}:                                 {},
+		{Group: "", Version: "v1", Kind: "ReplicationController"}:                           {},
+		{Group: "", Version: "v1", Kind: "ReplicationControllerList"}:                       {},
+		{Group: "", Version: "v1", Kind: "Secret"}:                                          {},
+		{Group: "", Version: "v1", Kind: "SecretList"}:                                      {},
+		{Group: "", Version: "v1", Kind: "Service"}:                                         {},
+		{Group: "", Version: "v1", Kind: "ServiceList"}:                                     {},
+		{Group: "apps", Version: "v1alpha1", Kind: "StatefulSet"}:                           {},
+		{Group: "apps", Version: "v1alpha1", Kind: "StatefulSetList"}:                       {},
+		{Group: "autoscaling", Version: "v1", Kind: "HorizontalPodAutoscaler"}:              {},
+		{Group: "autoscaling", Version: "v1", Kind: "HorizontalPodAutoscalerList"}:          {},
+		{Group: "batch", Version: "v1", Kind: "Job"}:                                        {},
+		{Group: "batch", Version: "v1", Kind: "JobList"}:                                    {},
+		{Group: "batch", Version: "v2alpha1", Kind: "Job"}:                                  {},
+		{Group: "batch", Version: "v2alpha1", Kind: "JobList"}:                              {},
+		{Group: "batch", Version: "v2alpha1", Kind: "JobTemplate"}:                          {},
+		{Group: "batch", Version: "v2alpha1", Kind: "ScheduledJob"}:                         {},
+		{Group: "batch", Version: "v2alpha1", Kind: "ScheduledJobList"}:                     {},
+		{Group: "componentconfig", Version: "v1alpha1", Kind: "KubeProxyConfiguration"}:     {},
+		{Group: "componentconfig", Version: "v1alpha1", Kind: "KubeSchedulerConfiguration"}: {},
+		{Group: "componentconfig", Version: "v1alpha1", Kind: "KubeletConfiguration"}:       {},
+		{Group: "kubeadm.k8s.io", Version: "v1alpha1", Kind: "MasterConfiguration"}:         {},
+		// This object contains only int fields which currently breaks the defaulting test because
+		// it's pretty stupid. Once we add non integer fields, we should uncomment this.
+		// {Group: "kubeadm.k8s.io", Version: "v1alpha1", Kind: "NodeConfiguration"}:                 {},
 		{Group: "extensions", Version: "v1beta1", Kind: "DaemonSet"}:                              {},
 		{Group: "extensions", Version: "v1beta1", Kind: "DaemonSetList"}:                          {},
 		{Group: "extensions", Version: "v1beta1", Kind: "Deployment"}:                             {},
diff --git a/pkg/api/testing/BUILD b/pkg/api/testing/BUILD
index 8f83fe3bd7..a89214e7c7 100644
--- a/pkg/api/testing/BUILD
+++ b/pkg/api/testing/BUILD
@@ -19,6 +19,7 @@ go_library(
     ],
     tags = ["automanaged"],
     deps = [
+        "//cmd/kubeadm/app/apis/kubeadm:go_default_library",
         "//pkg/api:go_default_library",
         "//pkg/api/resource:go_default_library",
         "//pkg/api/testapi:go_default_library",
diff --git a/pkg/api/testing/fuzzer.go b/pkg/api/testing/fuzzer.go
index cc6888e8e5..c95e67d652 100644
--- a/pkg/api/testing/fuzzer.go
+++ b/pkg/api/testing/fuzzer.go
@@ -23,6 +23,7 @@ import (
 	"strconv"
 	"testing"
 
+	"k8s.io/kubernetes/cmd/kubeadm/app/apis/kubeadm"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/api/resource"
 	"k8s.io/kubernetes/pkg/api/testapi"
@@ -538,6 +539,19 @@ func FuzzerFor(t *testing.T, version unversioned.GroupVersion, src rand.Source)
 			// Set the bytes field on the RawExtension
 			r.Raw = bytes
 		},
+		func(obj *kubeadm.MasterConfiguration, c fuzz.Continue) {
+			c.FuzzNoCustom(obj)
+			obj.KubernetesVersion = "v10"
+			obj.API.BindPort = 20
+			obj.Discovery.BindPort = 20
+			obj.Networking.ServiceSubnet = "foo"
+			obj.Networking.DNSDomain = "foo"
+		},
+		func(obj *kubeadm.NodeConfiguration, c fuzz.Continue) {
+			c.FuzzNoCustom(obj)
+			obj.APIPort = 20
+			obj.DiscoveryPort = 20
+		},
 	)
 	return f
 }