diff --git a/packages/happy-dom/src/storage/StorageFactory.ts b/packages/happy-dom/src/storage/StorageFactory.ts
index cfdf53506..b7bb4504a 100644
--- a/packages/happy-dom/src/storage/StorageFactory.ts
+++ b/packages/happy-dom/src/storage/StorageFactory.ts
@@ -41,7 +41,25 @@ export default class StorageFactory {
 				return storage[PropertySymbol.data][key] !== undefined;
 			},
 			defineProperty(storage: Storage, key: string, descriptor: PropertyDescriptor): boolean {
-				if (Storage.prototype.hasOwnProperty(key) || descriptor.value === undefined) {
+				if (Storage.prototype.hasOwnProperty(key)) {
+					if (descriptor.get || descriptor.set) {
+						Object.defineProperty(storage, key, {
+							...descriptor,
+							get: descriptor.get ? descriptor.get.bind(storage) : undefined,
+							set: descriptor.set ? descriptor.set.bind(storage) : undefined
+						});
+					} else {
+						Object.defineProperty(storage, key, {
+							...descriptor,
+							value:
+								typeof descriptor.value === 'function'
+									? descriptor.value.bind(storage)
+									: descriptor.value
+						});
+					}
+					return true;
+				}
+				if (descriptor.value === undefined) {
 					return false;
 				}
 				storage[PropertySymbol.data][key] = String(descriptor.value);
diff --git a/packages/happy-dom/test/storage/Storage.test.ts b/packages/happy-dom/test/storage/Storage.test.ts
index 713ac1b81..cbc5f390a 100644
--- a/packages/happy-dom/test/storage/Storage.test.ts
+++ b/packages/happy-dom/test/storage/Storage.test.ts
@@ -1,6 +1,6 @@
 import Storage from '../../src/storage/Storage.js';
 import StorageFactory from '../../src/storage/StorageFactory.js';
-import { beforeEach, describe, it, expect } from 'vitest';
+import { beforeEach, describe, it, expect, vi } from 'vitest';
 
 describe('Storage', () => {
 	let storage: Storage;
@@ -140,4 +140,12 @@ describe('Storage', () => {
 			expect(storage['key2']).toBe(undefined);
 		});
 	});
+
+	describe('vi.spyOn()', () => {
+		it('Should spy on a method.', () => {
+			const spy = vi.spyOn(storage, 'getItem');
+			storage.getItem('key1');
+			expect(spy).toHaveBeenCalled();
+		});
+	});
 });