diff --git a/lib/primitives/netaddress.js b/lib/primitives/netaddress.js
index cddf9232..105da261 100644
--- a/lib/primitives/netaddress.js
+++ b/lib/primitives/netaddress.js
@@ -244,9 +244,11 @@ NetAddress.prototype.setPort = function setPort(port) {
 NetAddress.prototype.fromHost = function fromHost(host, port, network) {
   network = Network.get(network);
 
+  assert(port >= 0 && port <= 0xffff);
+
   this.raw = IP.toBuffer(host);
   this.host = IP.toString(this.raw);
-  this.port = port || network.port;
+  this.port = port;
   this.services = NetAddress.DEFAULT_SERVICES;
   this.ts = network.now();