diff -r 000000000000 -r 6474c204b198 js/src/jit-test/tests/basic/bug821470.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/jit-test/tests/basic/bug821470.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+load(libdir + "asserts.js");
+
+assertThrowsInstanceOf(function () {
+    eval("function x() { 'use strict'; const x = 4; x = 3; }");
+}, TypeError);
+assertThrowsInstanceOf(function () {
+    Function("'use strict'; const x = x = 5;");
+}, TypeError)