diff --git a/staging/src/k8s.io/apiserver/pkg/apis/audit/fuzzer/fuzzer.go b/staging/src/k8s.io/apiserver/pkg/apis/audit/fuzzer/fuzzer.go
index 1ec4464c5b3..a7c4d69d63a 100644
--- a/staging/src/k8s.io/apiserver/pkg/apis/audit/fuzzer/fuzzer.go
+++ b/staging/src/k8s.io/apiserver/pkg/apis/audit/fuzzer/fuzzer.go
@@ -50,5 +50,20 @@ func Funcs(codecs runtimeserializer.CodecFactory) []interface{} {
 				}
 			}
 		},
+		func(o *audit.ObjectReference, c fuzz.Continue) {
+			c.FuzzNoCustom(o)
+			switch c.Intn(3) {
+			case 0:
+				// core api group
+				o.APIGroup = ""
+				o.APIVersion = "v1"
+			case 1:
+				// other group
+				o.APIGroup = "rbac.authorization.k8s.io"
+				o.APIVersion = "v1beta1"
+			default:
+				// use random value.
+			}
+		},
 	}
 }
diff --git a/staging/src/k8s.io/apiserver/pkg/apis/audit/types.go b/staging/src/k8s.io/apiserver/pkg/apis/audit/types.go
index cfea0550661..b9f60cfe03c 100644
--- a/staging/src/k8s.io/apiserver/pkg/apis/audit/types.go
+++ b/staging/src/k8s.io/apiserver/pkg/apis/audit/types.go
@@ -231,6 +231,11 @@ type ObjectReference struct {
 	Name string
 	// +optional
 	UID types.UID
+	// APIGroup is the name of the API group that contains the referred object.
+	// The empty string represents the core API group.
+	// +optional
+	APIGroup string
+	// APIVersion is the version of the API group that contains the referred object.
 	// +optional
 	APIVersion string
 	// +optional
diff --git a/staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1/conversion.go b/staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1/conversion.go
new file mode 100644
index 00000000000..5f9cc5c1e11
--- /dev/null
+++ b/staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1/conversion.go
@@ -0,0 +1,54 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+import (
+	"strings"
+
+	"k8s.io/apimachinery/pkg/conversion"
+	"k8s.io/apiserver/pkg/apis/audit"
+)
+
+func Convert_audit_ObjectReference_To_v1alpha1_ObjectReference(in *audit.ObjectReference, out *ObjectReference, s conversion.Scope) error {
+	// Begin by copying all fields
+	if err := autoConvert_audit_ObjectReference_To_v1alpha1_ObjectReference(in, out, s); err != nil {
+		return err
+	}
+	// empty string means the core api group
+	if in.APIGroup == "" {
+		out.APIVersion = in.APIVersion
+	} else {
+		out.APIVersion = in.APIGroup + "/" + in.APIVersion
+	}
+	return nil
+}
+
+func Convert_v1alpha1_ObjectReference_To_audit_ObjectReference(in *ObjectReference, out *audit.ObjectReference, s conversion.Scope) error {
+	// Begin by copying all fields
+	if err := autoConvert_v1alpha1_ObjectReference_To_audit_ObjectReference(in, out, s); err != nil {
+		return err
+	}
+	i := strings.LastIndex(in.APIVersion, "/")
+	if i == -1 {
+		// In fact it should always contain a "/"
+		out.APIVersion = in.APIVersion
+	} else {
+		out.APIGroup = in.APIVersion[:i]
+		out.APIVersion = in.APIVersion[i+1:]
+	}
+	return nil
+}
diff --git a/staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1/conversion_test.go b/staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1/conversion_test.go
new file mode 100644
index 00000000000..38918e75b36
--- /dev/null
+++ b/staging/src/k8s.io/apiserver/pkg/apis/audit/v1alpha1/conversion_test.go
@@ -0,0 +1,94 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1alpha1
+
+import (
+	"reflect"
+	"testing"
+
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	auditinternal "k8s.io/apiserver/pkg/apis/audit"
+)
+
+var scheme = runtime.NewScheme()
+
+func init() {
+	addKnownTypes(scheme)
+	internalGV := schema.GroupVersion{Group: auditinternal.GroupName, Version: runtime.APIVersionInternal}
+	scheme.AddKnownTypes(internalGV,
+		&auditinternal.Event{},
+	)
+	RegisterConversions(scheme)
+}
+
+func TestConversion(t *testing.T) {
+	scheme.Log(t)
+
+	testcases := []struct {
+		desc     string
+		old      *ObjectReference
+		expected *auditinternal.ObjectReference
+	}{
+		{
+			"core group",
+			&ObjectReference{
+				APIVersion: "/v1",
+			},
+			&auditinternal.ObjectReference{
+				APIVersion: "v1",
+				APIGroup:   "",
+			},
+		},
+		{
+			"other groups",
+			&ObjectReference{
+				APIVersion: "rbac.authorization.k8s.io/v1beta1",
+			},
+			&auditinternal.ObjectReference{
+				APIVersion: "v1beta1",
+				APIGroup:   "rbac.authorization.k8s.io",
+			},
+		},
+		{
+			"all empty",
+			&ObjectReference{},
+			&auditinternal.ObjectReference{},
+		},
+		{
+			"invalid apiversion should not cause painc",
+			&ObjectReference{
+				APIVersion: "invalid version without slash",
+			},
+			&auditinternal.ObjectReference{
+				APIVersion: "invalid version without slash",
+				APIGroup:   "",
+			},
+		},
+	}
+	for _, tc := range testcases {
+		t.Run(tc.desc, func(t *testing.T) {
+			internal := &auditinternal.ObjectReference{}
+			if err := scheme.Convert(tc.old, internal, nil); err != nil {
+				t.Errorf("unexpected error: %v", err)
+			}
+			if !reflect.DeepEqual(internal, tc.expected) {
+				t.Errorf("expected\n\t%#v, got \n\t%#v", tc.expected, internal)
+			}
+		})
+	}
+}
diff --git a/staging/src/k8s.io/apiserver/pkg/apis/audit/v1beta1/types.go b/staging/src/k8s.io/apiserver/pkg/apis/audit/v1beta1/types.go
index 1ecac858854..ccf6a039b02 100644
--- a/staging/src/k8s.io/apiserver/pkg/apis/audit/v1beta1/types.go
+++ b/staging/src/k8s.io/apiserver/pkg/apis/audit/v1beta1/types.go
@@ -225,10 +225,15 @@ type ObjectReference struct {
 	Name string `json:"name,omitempty" protobuf:"bytes,3,opt,name=name"`
 	// +optional
 	UID types.UID `json:"uid,omitempty" protobuf:"bytes,4,opt,name=uid,casttype=k8s.io/apimachinery/pkg/types.UID"`
+	// APIGroup is the name of the API group that contains the referred object.
+	// The empty string represents the core API group.
 	// +optional
-	APIVersion string `json:"apiVersion,omitempty" protobuf:"bytes,5,opt,name=apiVersion"`
+	APIGroup string `json:"apiGroup,omitempty" protobuf:"bytes,5,opt,name=apiGroup"`
+	// APIVersion is the version of the API group that contains the referred object.
 	// +optional
-	ResourceVersion string `json:"resourceVersion,omitempty" protobuf:"bytes,6,opt,name=resourceVersion"`
+	APIVersion string `json:"apiVersion,omitempty" protobuf:"bytes,6,opt,name=apiVersion"`
 	// +optional
-	Subresource string `json:"subresource,omitempty" protobuf:"bytes,7,opt,name=subresource"`
+	ResourceVersion string `json:"resourceVersion,omitempty" protobuf:"bytes,7,opt,name=resourceVersion"`
+	// +optional
+	Subresource string `json:"subresource,omitempty" protobuf:"bytes,8,opt,name=subresource"`
 }
diff --git a/staging/src/k8s.io/apiserver/pkg/audit/request.go b/staging/src/k8s.io/apiserver/pkg/audit/request.go
index 26807485c60..c2547ac3733 100644
--- a/staging/src/k8s.io/apiserver/pkg/audit/request.go
+++ b/staging/src/k8s.io/apiserver/pkg/audit/request.go
@@ -97,7 +97,8 @@ func NewEventFromRequest(req *http.Request, level auditinternal.Level, attribs a
 			Name:        attribs.GetName(),
 			Resource:    attribs.GetResource(),
 			Subresource: attribs.GetSubresource(),
-			APIVersion:  attribs.GetAPIGroup() + "/" + attribs.GetAPIVersion(),
+			APIGroup:    attribs.GetAPIGroup(),
+			APIVersion:  attribs.GetAPIVersion(),
 		}
 	}
 
@@ -132,6 +133,7 @@ func LogRequestObject(ae *audit.Event, obj runtime.Object, gvr schema.GroupVersi
 	}
 	// TODO: ObjectRef should include the API group.
 	if len(ae.ObjectRef.APIVersion) == 0 {
+		ae.ObjectRef.APIGroup = gvr.Group
 		ae.ObjectRef.APIVersion = gvr.Version
 	}
 	if len(ae.ObjectRef.Resource) == 0 {
diff --git a/staging/src/k8s.io/apiserver/pkg/endpoints/filters/audit_test.go b/staging/src/k8s.io/apiserver/pkg/endpoints/filters/audit_test.go
index c6e27981188..a5b483da02f 100644
--- a/staging/src/k8s.io/apiserver/pkg/endpoints/filters/audit_test.go
+++ b/staging/src/k8s.io/apiserver/pkg/endpoints/filters/audit_test.go
@@ -923,6 +923,12 @@ func TestAuditJson(t *testing.T) {
 			} else if expectedID != event.AuditID {
 				t.Errorf("[%s] Audits for one request should share the same AuditID, %s differs from %s", test.desc, expectedID, event.AuditID)
 			}
+			if event.ObjectRef.APIVersion != "v1" {
+				t.Errorf("[%s] Unexpected apiVersion: %s", test.desc, event.ObjectRef.APIVersion)
+			}
+			if event.ObjectRef.APIGroup != "" {
+				t.Errorf("[%s] Unexpected apiGroup: %s", test.desc, event.ObjectRef.APIGroup)
+			}
 			if (event.ResponseStatus == nil) != (expect.ResponseStatus == nil) {
 				t.Errorf("[%s] Unexpected ResponseStatus: %v", test.desc, event.ResponseStatus)
 				continue