diff --git a/index.d.ts b/index.d.ts
index dc47c85..5fa6689 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -1,4 +1,4 @@
-import {Primitive, JsonObject} from 'type-fest';
+import {type Primitive, type JsonObject} from 'type-fest';
 
 export {default as errorConstructors} from './error-constructors.js';
 
@@ -19,7 +19,7 @@ export type ErrorLike = {
 	code?: string;
 };
 
-export interface Options {
+export type Options = {
 	/**
 	The maximum depth of properties to preserve when serializing/deserializing.
 
@@ -47,7 +47,7 @@ export interface Options {
 	@default true
 	*/
 	readonly useToJSON?: boolean;
-}
+};
 
 /**
 Serialize an `Error` object into a plain object.
diff --git a/index.js b/index.js
index 22f4499..525ec3b 100644
--- a/index.js
+++ b/index.js
@@ -128,7 +128,7 @@ const destroyCircular = ({
 	}
 
 	for (const {property, enumerable} of commonProperties) {
-		if (typeof from[property] !== 'undefined' && from[property] !== null) {
+		if (from[property] !== undefined && from[property] !== null) {
 			Object.defineProperty(to, property, {
 				value: isErrorLike(from[property]) ? continueDestroyCircular(from[property]) : from[property],
 				enumerable: forceEnumerable ? true : enumerable,
diff --git a/index.test-d.ts b/index.test-d.ts
index ea7412e..a50b97b 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -1,5 +1,7 @@
 import {expectType, expectAssignable} from 'tsd';
-import {serializeError, deserializeError, ErrorObject, Options} from './index.js';
+import {
+	serializeError, deserializeError, type ErrorObject, type Options,
+} from './index.js';
 
 const error = new Error('unicorn');
 
diff --git a/package.json b/package.json
index d5886c5..d8bcdd8 100644
--- a/package.json
+++ b/package.json
@@ -38,11 +38,11 @@
 		"deserialize"
 	],
 	"dependencies": {
-		"type-fest": "^2.12.2"
+		"type-fest": "^4.31.0"
 	},
 	"devDependencies": {
-		"ava": "^4.2.0",
-		"tsd": "^0.20.0",
-		"xo": "^0.48.0"
+		"ava": "^6.2.0",
+		"tsd": "^0.31.2",
+		"xo": "^0.60.0"
 	}
 }
diff --git a/test.js b/test.js
index 45ced34..03c8615 100644
--- a/test.js
+++ b/test.js
@@ -119,7 +119,7 @@ test('should drop functions', t => {
 
 	const serialized = serializeError(object);
 	t.deepEqual(serialized, {});
-	t.false(Object.prototype.hasOwnProperty.call(serialized, 'a'));
+	t.false(Object.hasOwn(serialized, 'a'));
 });
 
 test('should not access deep non-enumerable properties', t => {
@@ -349,6 +349,17 @@ test('should deserialize properties up to `Options.maxDepth` levels deep', t =>
 	t.deepEqual(levelThree, error);
 });
 
+test('should ignore objects that look like errors but are not', t => {
+	const object = {
+		name: 'Error',
+		message: (new class {}('Foo')),
+		stack: 'at <anonymous>:3:14',
+	};
+
+	const deserialized = deserializeError(object);
+	t.deepEqual(deserialized, object);
+});
+
 test('should serialize Date as ISO string', t => {
 	const date = {date: new Date(0)};
 	const serialized = serializeError(date);
@@ -467,13 +478,19 @@ test('should serialize properties up to `Options.maxDepth` levels deep', t => {
 	t.deepEqual(levelZero, {});
 
 	const levelOne = serializeError(error, {maxDepth: 1});
-	t.deepEqual(levelOne, {message, name, stack, one: {}});
+	t.deepEqual(levelOne, {
+		message, name, stack, one: {},
+	});
 
 	const levelTwo = serializeError(error, {maxDepth: 2});
-	t.deepEqual(levelTwo, {message, name, stack, one: {two: {}}});
+	t.deepEqual(levelTwo, {
+		message, name, stack, one: {two: {}},
+	});
 
 	const levelThree = serializeError(error, {maxDepth: 3});
-	t.deepEqual(levelThree, {message, name, stack, one: {two: {three: {}}}});
+	t.deepEqual(levelThree, {
+		message, name, stack, one: {two: {three: {}}},
+	});
 });
 
 test('should identify serialized errors', t => {