diff --git a/pkg/registry/core/pod/storage/storage.go b/pkg/registry/core/pod/storage/storage.go
index 5017395f231..91dff4a0fa2 100644
--- a/pkg/registry/core/pod/storage/storage.go
+++ b/pkg/registry/core/pod/storage/storage.go
@@ -186,10 +186,10 @@ func (r *BindingREST) Create(ctx context.Context, name string, obj runtime.Objec
 	return
 }
 
-// setPodHostAndAnnotations sets the given pod's host to 'machine' if and only if it was
-// previously 'oldMachine' and merges the provided annotations with those of the pod.
+// setPodHostAndAnnotations sets the given pod's host to 'machine' if and only if
+// the pod is unassigned and merges the provided annotations with those of the pod.
 // Returns the current state of the pod, or an error.
-func (r *BindingREST) setPodHostAndAnnotations(ctx context.Context, podUID types.UID, podResourceVersion, podID, oldMachine, machine string, annotations map[string]string, dryRun bool) (finalPod *api.Pod, err error) {
+func (r *BindingREST) setPodHostAndAnnotations(ctx context.Context, podUID types.UID, podResourceVersion, podID, machine string, annotations map[string]string, dryRun bool) (finalPod *api.Pod, err error) {
 	podKey, err := r.store.KeyFunc(ctx, podID)
 	if err != nil {
 		return nil, err
@@ -214,7 +214,7 @@ func (r *BindingREST) setPodHostAndAnnotations(ctx context.Context, podUID types
 		if pod.DeletionTimestamp != nil {
 			return nil, fmt.Errorf("pod %s is being deleted, cannot be assigned to a host", pod.Name)
 		}
-		if pod.Spec.NodeName != oldMachine {
+		if pod.Spec.NodeName != "" {
 			return nil, fmt.Errorf("pod %v is already assigned to node %q", pod.Name, pod.Spec.NodeName)
 		}
 		pod.Spec.NodeName = machine
@@ -236,7 +236,7 @@ func (r *BindingREST) setPodHostAndAnnotations(ctx context.Context, podUID types
 
 // assignPod assigns the given pod to the given machine.
 func (r *BindingREST) assignPod(ctx context.Context, podUID types.UID, podResourceVersion, podID string, machine string, annotations map[string]string, dryRun bool) (err error) {
-	if _, err = r.setPodHostAndAnnotations(ctx, podUID, podResourceVersion, podID, "", machine, annotations, dryRun); err != nil {
+	if _, err = r.setPodHostAndAnnotations(ctx, podUID, podResourceVersion, podID, machine, annotations, dryRun); err != nil {
 		err = storeerr.InterpretGetError(err, api.Resource("pods"), podID)
 		err = storeerr.InterpretUpdateError(err, api.Resource("pods"), podID)
 		if _, ok := err.(*errors.StatusError); !ok {