diff --git a/.changeset/grumpy-students-smell.md b/.changeset/grumpy-students-smell.md
new file mode 100644
index 00000000..9372912b
--- /dev/null
+++ b/.changeset/grumpy-students-smell.md
@@ -0,0 +1,5 @@
+---
+"open-next": patch
+---
+
+fix: prevent duplication of location header
diff --git a/packages/open-next/src/adapters/routing/middleware.ts b/packages/open-next/src/adapters/routing/middleware.ts
index 86f825af..85eb02b3 100644
--- a/packages/open-next/src/adapters/routing/middleware.ts
+++ b/packages/open-next/src/adapters/routing/middleware.ts
@@ -123,18 +123,16 @@ export async function handleMiddleware(
   // If the middleware returned a Redirect, we set the `Location` header with
   // the redirected url and end the response.
   if (res.statusCode >= 300 && res.statusCode < 400) {
-    const location = result.response.headers
-      .get("location")
-      ?.replace("http://localhost:3000", `https://${req.headers.host}`);
+    resHeaders.location = resHeaders.location?.replace(
+      "http://localhost:3000",
+      `https://${req.headers.host}`,
+    );
     // res.setHeader("Location", location);
     return {
       body: "",
       type: internalEvent.type,
       statusCode: res.statusCode,
-      headers: {
-        ...resHeaders,
-        Location: location ?? "",
-      },
+      headers: resHeaders,
       isBase64Encoded: false,
     };
   }