diff --git a/test/parallel/test-http-set-trailers.js b/test/parallel/test-http-set-trailers.js
index 921c456bdaddfd..2197de9b0b229a 100644
--- a/test/parallel/test-http-set-trailers.js
+++ b/test/parallel/test-http-set-trailers.js
@@ -26,29 +26,18 @@ const http = require('http');
 const net = require('net');
 const util = require('util');
 
-let outstanding_reqs = 0;
-
-const server = http.createServer(function(req, res) {
-  res.writeHead(200, [['content-type', 'text/plain']]);
-  res.addTrailers({ 'x-foo': 'bar' });
-  res.end('stuff\n');
-});
-server.listen(0);
-
-
 // First, we test an HTTP/1.0 request.
-server.on('listening', function() {
-  const c = net.createConnection(this.address().port);
-  let res_buffer = '';
+function testHttp10(port, callback) {
+  const c = net.createConnection(port);
 
   c.setEncoding('utf8');
 
-  c.on('connect', function() {
-    outstanding_reqs++;
+  c.on('connect', () => {
     c.write('GET / HTTP/1.0\r\n\r\n');
   });
 
-  c.on('data', function(chunk) {
+  let res_buffer = '';
+  c.on('data', (chunk) => {
     res_buffer += chunk;
   });
 
@@ -56,61 +45,58 @@ server.on('listening', function() {
     c.end();
     assert.ok(
       !/x-foo/.test(res_buffer),
-      `Trailer in HTTP/1.0 response. Response buffer: ${res_buffer}`
+      `No trailer in HTTP/1.0 response. Response buffer: ${res_buffer}`
     );
-    outstanding_reqs--;
-    if (outstanding_reqs === 0) {
-      server.close();
-    }
+    callback();
   });
-});
+}
 
 // Now, we test an HTTP/1.1 request.
-server.on('listening', function() {
-  const c = net.createConnection(this.address().port);
-  let res_buffer = '';
-  let tid;
+function testHttp11(port, callback) {
+  const c = net.createConnection(port);
 
   c.setEncoding('utf8');
 
+  let tid;
   c.on('connect', function() {
-    outstanding_reqs++;
     c.write('GET / HTTP/1.1\r\n\r\n');
     tid = setTimeout(common.mustNotCall(), 2000, 'Couldn\'t find last chunk.');
   });
 
+  let res_buffer = '';
   c.on('data', function(chunk) {
     res_buffer += chunk;
     if (/0\r\n/.test(res_buffer)) { // got the end.
-      outstanding_reqs--;
       clearTimeout(tid);
       assert.ok(
         /0\r\nx-foo: bar\r\n\r\n$/.test(res_buffer),
         `No trailer in HTTP/1.1 response. Response buffer: ${res_buffer}`
       );
-      if (outstanding_reqs === 0) {
-        server.close();
-      }
+      callback();
     }
   });
-});
+}
 
 // Now, see if the client sees the trailers.
-server.on('listening', function() {
-  http.get({
-    port: this.address().port,
-    path: '/hello',
-    headers: {}
-  }, function(res) {
+function testClientTrailers(port, callback) {
+  http.get({ port, path: '/hello', headers: {} }, (res) => {
     res.on('end', function() {
       assert.ok('x-foo' in res.trailers,
                 `${util.inspect(res.trailers)} misses the 'x-foo' property`);
-      outstanding_reqs--;
-      if (outstanding_reqs === 0) {
-        server.close();
-      }
+      callback();
     });
     res.resume();
   });
-  outstanding_reqs++;
+}
+
+const server = http.createServer((req, res) => {
+  res.writeHead(200, [['content-type', 'text/plain']]);
+  res.addTrailers({ 'x-foo': 'bar' });
+  res.end('stuff\n');
+});
+server.listen(0, () => {
+  Promise.all([testHttp10, testHttp11, testClientTrailers]
+    .map(util.promisify)
+    .map((f) => f(server.address().port)))
+    .then(() => server.close());
 });