diff --git a/pkg/controller/statefulset/BUILD b/pkg/controller/statefulset/BUILD
index 011c91b0742..bfb3e41ab65 100644
--- a/pkg/controller/statefulset/BUILD
+++ b/pkg/controller/statefulset/BUILD
@@ -19,6 +19,7 @@ go_library(
     ],
     tags = ["automanaged"],
     deps = [
+        "//pkg/api:go_default_library",
         "//pkg/api/v1/pod:go_default_library",
         "//pkg/client/retry:go_default_library",
         "//pkg/controller:go_default_library",
diff --git a/pkg/controller/statefulset/stateful_set.go b/pkg/controller/statefulset/stateful_set.go
index 2163fd94f3e..e5c2be07f90 100644
--- a/pkg/controller/statefulset/stateful_set.go
+++ b/pkg/controller/statefulset/stateful_set.go
@@ -39,6 +39,7 @@ import (
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/tools/record"
 	"k8s.io/client-go/util/workqueue"
+	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/controller"
 	"k8s.io/kubernetes/pkg/controller/history"
 
@@ -450,7 +451,12 @@ func (ssc *StatefulSetController) sync(key string) error {
 // syncStatefulSet syncs a tuple of (statefulset, []*v1.Pod).
 func (ssc *StatefulSetController) syncStatefulSet(set *apps.StatefulSet, pods []*v1.Pod) error {
 	glog.V(4).Infof("Syncing StatefulSet %v/%v with %d pods", set.Namespace, set.Name, len(pods))
-	if err := ssc.control.UpdateStatefulSet(set, pods); err != nil {
+	// TODO: investigate where we mutate the set during the update as it is not obvious.
+	setCopy, err := api.Scheme.DeepCopy(set)
+	if err != nil {
+		return err
+	}
+	if err := ssc.control.UpdateStatefulSet(setCopy.(*apps.StatefulSet), pods); err != nil {
 		return err
 	}
 	glog.V(4).Infof("Successfully synced StatefulSet %s/%s successful", set.Namespace, set.Name)