diff --git a/test/parallel/test-zlib-close-after-write.js b/test/parallel/test-zlib-close-after-write.js
index d89102ed8c7fd9..211318dc5ad6cc 100644
--- a/test/parallel/test-zlib-close-after-write.js
+++ b/test/parallel/test-zlib-close-after-write.js
@@ -23,7 +23,7 @@
 const common = require('../common');
 const zlib = require('zlib');
 
-zlib.gzip('hello', common.mustCall(function(err, out) {
+zlib.gzip('hello', common.mustCall((err, out) => {
   const unzip = zlib.createGunzip();
   unzip.write(out);
   unzip.close(common.mustCall());