diff --git a/staging/src/k8s.io/apimachinery/pkg/util/managedfields/gvkparser.go b/staging/src/k8s.io/apimachinery/pkg/util/managedfields/gvkparser.go
index 838357f2e3e..0cc228af936 100644
--- a/staging/src/k8s.io/apimachinery/pkg/util/managedfields/gvkparser.go
+++ b/staging/src/k8s.io/apimachinery/pkg/util/managedfields/gvkparser.go
@@ -69,7 +69,7 @@ func NewGVKParser(models proto.Models, preserveUnknownFields bool) (*GvkParser,
 			if len(gvk.Kind) > 0 {
 				_, ok := parser.gvks[gvk]
 				if ok {
-					//return nil, fmt.Errorf("duplicate entry for %v", gvk)
+					return nil, fmt.Errorf("duplicate entry for %v", gvk)
 				}
 				parser.gvks[gvk] = modelName
 			}
diff --git a/staging/src/k8s.io/client-go/applyconfigurations/meta/v1/unstructured.go b/staging/src/k8s.io/client-go/applyconfigurations/meta/v1/unstructured.go
index 27f70db125f..040a6adbd97 100644
--- a/staging/src/k8s.io/client-go/applyconfigurations/meta/v1/unstructured.go
+++ b/staging/src/k8s.io/client-go/applyconfigurations/meta/v1/unstructured.go
@@ -1,5 +1,5 @@
 /*
-Copyright The Kubernetes Authors.
+Copyright 2021 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.