diff --git a/lib/js/test262-runner.py b/lib/js/test262-runner.py
index 580c4b11..0fa15c97 100644
--- a/lib/js/test262-runner.py
+++ b/lib/js/test262-runner.py
@@ -109,6 +109,8 @@ var __assert_call__ = function (b, m) {
   if (b) { return; }
   throw new Test262Error(m || "assertion failed");
 };
+// Make `assert` itself callable — many tests write `assert(x, "msg")`.
+assert.__callable__ = __assert_call__;
 // compareArray stub — minimal for cases that only compareArray arrays of primitives
 assert.compareArray = function (a, b, m) {
   var msg = m || "";
@@ -128,12 +130,12 @@ var verifyProperty = function (obj, name, desc, opts) {
   }
 };
 var verifyPrimordialProperty = verifyProperty;
-var verifyNotEnumerable = function (o, n) { };
-var verifyNotWritable = function (o, n) { };
-var verifyNotConfigurable = function (o, n) { };
-var verifyEnumerable = function (o, n) { };
-var verifyWritable = function (o, n) { };
-var verifyConfigurable = function (o, n) { };
+var verifyNotEnumerable = function (o, n, v, w, x) { };
+var verifyNotWritable = function (o, n, v, w, x) { };
+var verifyNotConfigurable = function (o, n, v, w, x) { };
+var verifyEnumerable = function (o, n, v, w, x) { };
+var verifyWritable = function (o, n, v, w, x) { };
+var verifyConfigurable = function (o, n, v, w, x) { };
 // isConstructor stub — we can't actually probe; assume falsy constructor for arrows/functions
 var isConstructor = function (f) {
   if (typeof f !== "function") { return false; }