diff --git a/src/lib/__tests__/detect.test.ts b/src/lib/__tests__/detect.test.ts
index 0395aef5..c41523d1 100644
--- a/src/lib/__tests__/detect.test.ts
+++ b/src/lib/__tests__/detect.test.ts
@@ -18,5 +18,5 @@ test('getIpAddress: Standard header', () => {
 });
 
 test('getIpAddress: No header', () => {
-  expect(getIpAddress(new Headers())).toEqual(null);
+  expect(getIpAddress(new Headers())).toEqual(undefined);
 });