diff --git a/examples/spec/finalizationregistry.js b/examples/spec/finalizationregistry.js
new file mode 100644
index 0000000..e29094f
--- /dev/null
+++ b/examples/spec/finalizationregistry.js
@@ -0,0 +1,28 @@
+import { test, summary } from './helpers.js';
+
+console.log('FinalizationRegistry Tests\n');
+
+let callbackCalled = false;
+const fr = new FinalizationRegistry(function(heldValue) {
+  callbackCalled = true;
+});
+
+test('finalizationregistry instanceof', fr instanceof FinalizationRegistry, true);
+test('finalizationregistry prototype', Object.getPrototypeOf(fr) === FinalizationRegistry.prototype, true);
+test('finalizationregistry has register', typeof fr.register, 'function');
+test('finalizationregistry has unregister', typeof fr.unregister, 'function');
+
+const target = {};
+const token = {};
+fr.register(target, 'held value', token);
+
+test('finalizationregistry register returns undefined', fr.register({}, 'test'), undefined);
+
+const unregisterResult = fr.unregister(token);
+test('finalizationregistry unregister returns boolean', typeof unregisterResult, 'boolean');
+test('finalizationregistry unregister found token', unregisterResult, true);
+
+const notFoundResult = fr.unregister({});
+test('finalizationregistry unregister not found', notFoundResult, false);
+
+summary();
diff --git a/examples/spec/weakref.js b/examples/spec/weakref.js
new file mode 100644
index 0000000..a8aaede
--- /dev/null
+++ b/examples/spec/weakref.js
@@ -0,0 +1,21 @@
+import { test, summary } from './helpers.js';
+
+console.log('WeakRef Tests\n');
+
+const obj1 = { name: 'test' };
+const ref1 = new WeakRef(obj1);
+
+test('weakref deref returns target', ref1.deref() === obj1, true);
+test('weakref deref value', ref1.deref().name, 'test');
+
+const obj2 = { value: 42 };
+const ref2 = new WeakRef(obj2);
+test('weakref deref number value', ref2.deref().value, 42);
+
+const obj3 = {};
+const ref3 = new WeakRef(obj3);
+test('weakref has deref method', typeof ref3.deref, 'function');
+test('weakref instanceof', ref3 instanceof WeakRef, true);
+test('weakref prototype', Object.getPrototypeOf(ref3) === WeakRef.prototype, true);
+
+summary();