diff --git a/staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/types.go b/staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/types.go
index 917efb37f75..e93df18461e 100644
--- a/staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/types.go
+++ b/staging/src/k8s.io/apimachinery/pkg/apis/meta/v1/types.go
@@ -799,7 +799,8 @@ type APIGroup struct {
 	// The server returns only those CIDRs that it thinks that the client can match.
 	// For example: the master will return an internal IP CIDR only, if the client reaches the server using an internal IP.
 	// Server looks at X-Forwarded-For header or X-Real-Ip header or request.RemoteAddr (in that order) to get the client IP.
-	ServerAddressByClientCIDRs []ServerAddressByClientCIDR `json:"serverAddressByClientCIDRs" protobuf:"bytes,4,rep,name=serverAddressByClientCIDRs"`
+	// +optional
+	ServerAddressByClientCIDRs []ServerAddressByClientCIDR `json:"serverAddressByClientCIDRs,omitempty" protobuf:"bytes,4,rep,name=serverAddressByClientCIDRs"`
 }
 
 // ServerAddressByClientCIDR helps the client to determine the server address that they should use, depending on the clientCIDR that they match.