diff --git a/tests/baselines/reference/typeofClassExpression1.js b/tests/baselines/reference/typeofClassExpression1.js
index 84e35bc2d25..574d291b946 100644
--- a/tests/baselines/reference/typeofClassExpression1.js
+++ b/tests/baselines/reference/typeofClassExpression1.js
@@ -129,6 +129,8 @@ var __extends = (this && this.__extends) || (function () {
         return extendStatics(d, b);
     };
     return function (d, b) {
+        if (typeof b !== "function" && b !== null)
+            throw new TypeError("Class extends value " + String(b) + " is not a constructor or null");
         extendStatics(d, b);
         function __() { this.constructor = d; }
         d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());