diff --git a/lib/dns.js b/lib/dns.js
index 782cdfa3f7..6683eacf14 100644
--- a/lib/dns.js
+++ b/lib/dns.js
@@ -189,6 +189,9 @@ exports.lookupService = function(host, port, callback) {
   if (cares.isIP(host) === 0)
     throw new TypeError('host needs to be a valid IP address');
 
+  if (typeof port !== 'number')
+    throw new TypeError(`port argument must be a number, got "${port}"`);
+
   callback = makeAsync(callback);
 
   var req = new GetNameInfoReqWrap();
diff --git a/test/parallel/test-dns.js b/test/parallel/test-dns.js
index 3362e8c534..04264907d3 100644
--- a/test/parallel/test-dns.js
+++ b/test/parallel/test-dns.js
@@ -145,3 +145,19 @@ assert.doesNotThrow(function() {
     hints: dns.ADDRCONFIG | dns.V4MAPPED
   }, noop);
 });
+
+assert.throws(function() {
+  dns.lookupService('0.0.0.0');
+}, /invalid arguments/);
+
+assert.throws(function() {
+  dns.lookupService('fasdfdsaf', 0, noop);
+}, /host needs to be a valid IP address/);
+
+assert.throws(function() {
+  dns.lookupService('0.0.0.0', '0', noop);
+}, /port argument must be a number, got "0"/);
+
+assert.doesNotThrow(function() {
+  dns.lookupService('0.0.0.0', 0, noop);
+});