diff --git a/test/harness/nans.js b/test/harness/nans.js
index 51a16ba788ead6e7bd5251b3ae12ec6f232d1b3c..b228838d05ee28e013aaf66669a99e5ae860e7f5 100644
--- a/test/harness/nans.js
+++ b/test/harness/nans.js
@@ -1,4 +1,4 @@
-// Copyright (C) 2017 Rick Waldron, 2016 the V8 project authors.
+// Copyright (C) 2017 Rick Waldron, 2016 the V8 project authors. All rights reserved.
 // This code is governed by the BSD license found in the LICENSE file.
 /*---
 description: >
@@ -11,8 +11,8 @@ description: >
 includes: [nans.js]
 ---*/
 
-assert.sameValue(isNaN(distinctNaNs[0]), true);
-assert.sameValue(isNaN(distinctNaNs[1]), true);
-assert.sameValue(isNaN(distinctNaNs[2]), true);
-assert.sameValue(isNaN(distinctNaNs[3]), true);
-assert.sameValue(isNaN(distinctNaNs[4]), true);
+assert.sameValue(Number.isNaN(distinctNaNs[0]), true);
+assert.sameValue(Number.isNaN(distinctNaNs[1]), true);
+assert.sameValue(Number.isNaN(distinctNaNs[2]), true);
+assert.sameValue(Number.isNaN(distinctNaNs[3]), true);
+assert.sameValue(Number.isNaN(distinctNaNs[4]), true);