diff --git a/src/pages/api/auth.astro b/src/pages/api/auth.astro
index fa1d357..44add1c 100644
--- a/src/pages/api/auth.astro
+++ b/src/pages/api/auth.astro
@@ -4,7 +4,7 @@ import { GET } from "./auth"
 
 const auth = await GET(Astro.url.origin)
 
-const receiveMessage = (message) => {
+const receiveMessage = (message: MessageEvent) => {
   window.opener.postMessage(
     "authorization:github:${status}:${JSON.stringify(content)}",
     message.origin