diff --git a/staging/src/k8s.io/apimachinery/pkg/watch/watch.go b/staging/src/k8s.io/apimachinery/pkg/watch/watch.go
index fd0550e4a7a..b6c7bbfa8fa 100644
--- a/staging/src/k8s.io/apimachinery/pkg/watch/watch.go
+++ b/staging/src/k8s.io/apimachinery/pkg/watch/watch.go
@@ -27,11 +27,11 @@ import (
 
 // Interface can be implemented by anything that knows how to watch and report changes.
 type Interface interface {
-	// Stops watching. Will close the channel returned by ResultChan(). Releases
+	// Stop stops watching. Will close the channel returned by ResultChan(). Releases
 	// any resources used by the watch.
 	Stop()
 
-	// Returns a chan which will receive all the events. If an error occurs
+	// ResultChan returns a chan which will receive all the events. If an error occurs
 	// or Stop() is called, the implementation will close this channel and
 	// release any resources used by the watch.
 	ResultChan() <-chan Event
diff --git a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/response.go b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/response.go
index 640378d9a74..55b83af0c3b 100644
--- a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/response.go
+++ b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/response.go
@@ -59,8 +59,14 @@ func doTransformObject(ctx context.Context, obj runtime.Object, opts interface{}
 	if _, ok := obj.(*metav1.Status); ok {
 		return obj, nil
 	}
-	if err := ensureNonNilItems(obj); err != nil {
-		return nil, err
+
+	// ensure that for empty lists we don't return <nil> items.
+	// This is safe to modify without deep-copying the object, as
+	// List objects themselves are never cached.
+	if meta.IsListType(obj) && meta.LenList(obj) == 0 {
+		if err := meta.SetList(obj, []runtime.Object{}); err != nil {
+			return nil, err
+		}
 	}
 
 	switch target := mediaType.Convert; {
diff --git a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/rest.go b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/rest.go
index b40423dac34..15e3d9f7f1e 100644
--- a/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/rest.go
+++ b/staging/src/k8s.io/apiserver/pkg/endpoints/handlers/rest.go
@@ -356,16 +356,6 @@ func dedupOwnerReferencesAndAddWarning(obj runtime.Object, requestContext contex
 	}
 }
 
-// ensureNonNilItems ensures that for empty lists we don't return <nil> items.
-func ensureNonNilItems(obj runtime.Object) error {
-	if meta.IsListType(obj) && meta.LenList(obj) == 0 {
-		if err := meta.SetList(obj, []runtime.Object{}); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
 func summarizeData(data []byte, maxLength int) string {
 	switch {
 	case len(data) == 0: