diff --git a/net/ip.go b/net/ip.go
index cea4c6d5edb5f6734fbba8c5063a1b48d7dd6f30..920e871eef7396fbe54d2bf633b035677efc3d9f 100644
--- a/net/ip.go
+++ b/net/ip.go
@@ -26,7 +26,7 @@ func IPFromProtoIP(addr api.IP) IP {
 // ToProto converts an IP to a proto IP
 func (ip IP) ToProto() *api.IP {
 	ver := api.IP_IPv6
-	if ip.IsLegacy() {
+	if ip.isLegacy {
 		ver = api.IP_IPv4
 	}