diff --git a/staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/mutating/admission.go b/staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/mutating/admission.go
index ec0ae942b69..6d62a36f629 100644
--- a/staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/mutating/admission.go
+++ b/staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/mutating/admission.go
@@ -174,7 +174,7 @@ func (a *MutatingWebhook) ValidateInitialization() error {
 		return fmt.Errorf("MutatingWebhook.convertor is not properly setup: %v", err)
 	}
 	if a.defaulter == nil {
-		return fmt.Errorf("MutatingWebhook.defaulter is not properly setup: %v")
+		return fmt.Errorf("MutatingWebhook.defaulter is not properly setup")
 	}
 	go a.hookSource.Run(wait.NeverStop)
 	return nil