diff --git a/harness/sm/non262.js b/harness/sm/non262.js
index 5148960a2b..89df923246 100644
--- a/harness/sm/non262.js
+++ b/harness/sm/non262.js
@@ -1,5 +1,5 @@
 /*---
-defines: [assertThrownErrorContains, assertThrowsInstanceOfWithMessageCheck, newGlobal, print, assertEq, reportCompare, reportMatch, createIsHTMLDDA, createExternalArrayBuffer]
+defines: [assertThrownErrorContains, assertThrowsInstanceOfWithMessageCheck, newGlobal, print, assertEq, reportCompare, createIsHTMLDDA, createExternalArrayBuffer]
 ---*/
 
 function assertThrownErrorContains(f, substr) {
@@ -43,13 +43,6 @@ function reportCompare(...args) {
   assert.sameValue(...args)
 }
 
-function reportMatch(expectedRegExp, actual, description = "") {
-  assert.sameValue(typeof actual, "string",
-    `Type mismatch, expected string, actual type ${typeof actual}`);
-  assert.notSameValue(expectedRegExp.exec(actual), null,
-    `Expected match to '${expectedRegExp}', Actual value '${actual}'`);
-}
-
 if (globalThis.createIsHTMLDDA === undefined) {
   globalThis.createIsHTMLDDA = function createIsHTMLDDA() {
     return $262.IsHTMLDDA;
diff --git a/test/staging/sm/Function/function-toString-builtin.js b/test/staging/sm/Function/function-toString-builtin.js
index eff9465de7..1a4a549c53 100644
--- a/test/staging/sm/Function/function-toString-builtin.js
+++ b/test/staging/sm/Function/function-toString-builtin.js
@@ -2,52 +2,29 @@
 // This code is governed by the BSD license found in the LICENSE file.
 
 /*---
-includes: [sm/non262.js, sm/non262-shell.js]
-flags:
-  - noStrict
+includes: [nativeFunctionMatcher.js]
 description: |
   pending
 esid: pending
 ---*/
 
-// Greatly (!) simplified patterns for the PropertyName production.
-var propertyName = [
-    // PropertyName :: LiteralPropertyName :: IdentifierName
-    "\\w+",
-
-    // PropertyName :: LiteralPropertyName :: StringLiteral
-    "(?:'[^']*')",
-    "(?:\"[^\"]*\")",
-
-    // PropertyName :: LiteralPropertyName :: NumericLiteral
-    "\\d+",
-
-    // PropertyName :: ComputedPropertyName
-    "(?:\\[[^\\]]+\\])",
-].join("|")
-
-var nativeCode = RegExp([
-    "^", "function", "(get|set)?", ("(" + propertyName + ")?"), "\\(", "\\)", "\\{", "\\[native code\\]", "\\}", "$"
-].join("\\s*"));
-
-
 // Bound functions are considered built-ins.
-reportMatch(nativeCode, function(){}.bind().toString());
-reportMatch(nativeCode, function fn(){}.bind().toString());
+assertNativeFunction(function(){}.bind());
+assertNativeFunction(function fn(){}.bind());
 
 // Built-ins which are well-known intrinsic objects.
-reportMatch(nativeCode, Array.toString());
-reportMatch(nativeCode, Object.prototype.toString.toString());
-reportMatch(nativeCode, decodeURI.toString());
+assertNativeFunction(Array);
+assertNativeFunction(Object.prototype.toString);
+assertNativeFunction(decodeURI);
 
 // Other built-in functions.
-reportMatch(nativeCode, Math.asin.toString());
-reportMatch(nativeCode, String.prototype.blink.toString());
-reportMatch(nativeCode, RegExp.prototype[Symbol.split].toString());
+assertNativeFunction(Math.asin);
+assertNativeFunction(String.prototype.blink);
+assertNativeFunction(RegExp.prototype[Symbol.split]);
 
 // Built-in getter functions.
-reportMatch(nativeCode, Object.getOwnPropertyDescriptor(RegExp.prototype, "flags").get.toString());
-reportMatch(nativeCode, Object.getOwnPropertyDescriptor(Object.prototype, "__proto__").get.toString());
+assertNativeFunction(Object.getOwnPropertyDescriptor(RegExp.prototype, "flags").get);
+assertNativeFunction(Object.getOwnPropertyDescriptor(Object.prototype, "__proto__").get);
 
 // Built-in setter functions.
-reportMatch(nativeCode, Object.getOwnPropertyDescriptor(Object.prototype, "__proto__").set.toString());
+assertNativeFunction(Object.getOwnPropertyDescriptor(Object.prototype, "__proto__").set);