diff --git a/index.ts b/index.ts
index f4feb2f..5dfbf91 100644
--- a/index.ts
+++ b/index.ts
@@ -55,6 +55,11 @@ export default function diff(
 			);
 		} else if (
 			objKey !== newObjKey &&
+			!(
+				// treat NaN values as equivalent
+				typeof objKey === "number" && isNaN(objKey) &&
+				typeof newObjKey === "number" && isNaN(newObjKey)
+			) &&
 			!(
 				areObjects &&
 				(isNaN(objKey)
diff --git a/tests/nan.js b/tests/nan.js
new file mode 100644
index 0000000..e55ea84
--- /dev/null
+++ b/tests/nan.js
@@ -0,0 +1,69 @@
+import { test } from "uvu";
+import * as assert from "uvu/assert";
+
+import diff from "../dist/index.js";
+
+test("new NaN value in object", () => {
+	assert.equal(diff({}, { testNaN: NaN }), [
+		{
+			type: "CREATE",
+			path: ["testNaN"],
+			value: NaN,
+		},
+	]);
+});
+test("change NaN value in object", () => {
+	assert.equal(diff({ testNaN: NaN }, { testNaN: 0 }), [
+		{
+			type: "CHANGE",
+			path: ["testNaN"],
+			value: 0,
+			oldValue: NaN,
+		},
+	]);
+});
+test("do not change NaN value in object", () => {
+	assert.equal(diff({ testNaN: NaN }, { testNaN: NaN }), []);
+});
+test("remove NaN value in object", () => {
+	assert.equal(diff({ testNaN: NaN }, {}), [
+		{
+			type: "REMOVE",
+			path: ["testNaN"],
+			oldValue: NaN,
+		},
+	]);
+});
+test("new NaN value in array", () => {
+	assert.equal(diff([], [NaN]), [
+		{
+			type: "CREATE",
+			path: [0],
+			value: NaN,
+		},
+	]);
+});
+test("change NaN value in object", () => {
+	assert.equal(diff([NaN], [0]), [
+		{
+			type: "CHANGE",
+			path: [0],
+			value: 0,
+			oldValue: NaN,
+		},
+	]);
+});
+test("do not change NaN value in array", () => {
+	assert.equal(diff([NaN], [NaN]), []);
+});
+test("remove NaN value in array", () => {
+	assert.equal(diff([NaN], []), [
+		{
+			type: "REMOVE",
+			path: [0],
+			oldValue: NaN,
+		},
+	]);
+});
+
+test.run();