diff --git a/test/support/sws.js b/test/support/sws.js
index 7be774e..51d9a95 100644
--- a/test/support/sws.js
+++ b/test/support/sws.js
@@ -1,14 +1,9 @@
-var stream = require('stream')
-var util = require('util')
+const { Writable } = require('node:stream')
 
-module.exports = SlowWriteStream
-
-function SlowWriteStream () {
-  stream.Writable.call(this)
+class SlowWriteStream extends Writable {
+  _write (chunk, encoding, callback) {
+    setTimeout(callback, 1000)
+  }
 }
 
-util.inherits(SlowWriteStream, stream.Writable)
-
-SlowWriteStream.prototype._write = function _write (chunk, encoding, callback) {
-  setTimeout(callback, 1000)
-}
+module.exports = SlowWriteStream