diff --git a/pkg/controller/petset/fakes.go b/pkg/controller/petset/fakes.go
index 8c366990a83..5248d1d3e52 100644
--- a/pkg/controller/petset/fakes.go
+++ b/pkg/controller/petset/fakes.go
@@ -248,7 +248,7 @@ func (f *fakePetClient) deletePetAtIndex(index int) {
 }
 
 func (f *fakePetClient) setHealthy(index int) error {
-	if len(f.pets) < index {
+	if len(f.pets) <= index {
 		return fmt.Errorf("Index out of range, len %v index %v", len(f.pets), index)
 	}
 	f.pets[index].pod.Status.Phase = api.PodRunning
@@ -270,7 +270,7 @@ func (f *fakePetClient) isHealthy(pod *api.Pod) bool {
 }
 
 func (f *fakePetClient) setDeletionTimestamp(index int) error {
-	if len(f.pets) < index {
+	if len(f.pets) <= index {
 		return fmt.Errorf("Index out of range, len %v index %v", len(f.pets), index)
 	}
 	f.pets[index].pod.DeletionTimestamp = &unversioned.Time{Time: time.Now()}
diff --git a/pkg/controller/petset/pet_set_test.go b/pkg/controller/petset/pet_set_test.go
index e1a3dc24598..0e05d37fa52 100644
--- a/pkg/controller/petset/pet_set_test.go
+++ b/pkg/controller/petset/pet_set_test.go
@@ -73,7 +73,7 @@ func scalePetSet(t *testing.T, ps *apps.PetSet, psc *PetSetController, fc *fakeP
 	for i := 0; i < scale; i++ {
 		pl := fc.getPodList()
 		if len(pl) != i {
-			t.Errorf("Unexpected number of pets, expected %d found %d", i, len(fc.pets))
+			t.Errorf("Unexpected number of pets, expected %d found %d", i, len(pl))
 		}
 		if _, syncErr := psc.syncPetSet(ps, pl); syncErr != nil {
 			errs = append(errs, syncErr)
@@ -120,7 +120,7 @@ func TestPetSetControllerDeletes(t *testing.T) {
 	knownPods := fc.getPodList()
 	for i := replicas - 1; i >= 0; i-- {
 		if len(fc.pets) != i+1 {
-			t.Errorf("Unexpected number of pets, expected %d found %d", i, len(fc.pets))
+			t.Errorf("Unexpected number of pets, expected %d found %d", i+1, len(fc.pets))
 		}
 		if _, syncErr := psc.syncPetSet(ps, knownPods); syncErr != nil {
 			errs = append(errs, syncErr)