diff --git a/src/lib/__tests__/detect.test.ts b/src/lib/__tests__/detect.test.ts
index 14c67dde..1cb558ad 100644
--- a/src/lib/__tests__/detect.test.ts
+++ b/src/lib/__tests__/detect.test.ts
@@ -6,17 +6,17 @@ const IP = '127.0.0.1';
 test('getIpAddress: Custom header', () => {
   process.env.CLIENT_IP_HEADER = 'x-custom-ip-header';
 
-  expect(detect.getIpAddress({ headers: { 'x-custom-ip-header': IP } } as any)).toEqual(IP);
+  expect(detect.getIpAddress(new Headers({ 'x-custom-ip-header': IP }))).toEqual(IP);
 });
 
 test('getIpAddress: CloudFlare header', () => {
-  expect(detect.getIpAddress({ headers: { 'cf-connecting-ip': IP } } as any)).toEqual(IP);
+  expect(detect.getIpAddress(new Headers({ 'cf-connecting-ip': IP }))).toEqual(IP);
 });
 
 test('getIpAddress: Standard header', () => {
-  expect(detect.getIpAddress({ headers: { 'x-forwarded-for': IP } } as any)).toEqual(IP);
+  expect(detect.getIpAddress(new Headers({ 'x-forwarded-for': IP }))).toEqual(IP);
 });
 
 test('getIpAddress: No header', () => {
-  expect(detect.getIpAddress({ headers: {} } as any)).toEqual(null);
+  expect(detect.getIpAddress(new Headers())).toEqual(null);
 });
diff --git a/src/lib/detect.ts b/src/lib/detect.ts
index 89e73a0b..9f1e04b7 100644
--- a/src/lib/detect.ts
+++ b/src/lib/detect.ts
@@ -28,7 +28,7 @@ export function getIpAddress(headers: Headers) {
   const ip = headers.get(header);
 
   if (header === 'x-forwarded-for') {
-    return ip?.split[',']?.[0]?.trim();
+    return ip?.split(',')?.[0]?.trim();
   }
 
   if (header === 'forwarded') {