diff --git a/test/parallel/test-cluster-setup-master-argv.js b/test/parallel/test-cluster-setup-master-argv.js
index e570af7cd52a60..32c5a91b3caab4 100644
--- a/test/parallel/test-cluster-setup-master-argv.js
+++ b/test/parallel/test-cluster-setup-master-argv.js
@@ -1,16 +1,16 @@
 'use strict';
-var common = require('../common');
-var assert = require('assert');
-var cluster = require('cluster');
+const common = require('../common');
+const assert = require('assert');
+const cluster = require('cluster');
 
 setTimeout(common.fail.bind(assert, 'setup not emitted'), 1000).unref();
 
-cluster.on('setup', function() {
+cluster.on('setup', common.mustCall(function() {
   var clusterArgs = cluster.settings.args;
   var realArgs = process.argv;
   assert.strictEqual(clusterArgs[clusterArgs.length - 1],
                      realArgs[realArgs.length - 1]);
-});
+}));
 
 assert.notStrictEqual(process.argv[process.argv.length - 1], 'OMG,OMG');
 process.argv.push('OMG,OMG');