diff --git a/.changeset/giant-days-develop.md b/.changeset/giant-days-develop.md
new file mode 100644
index 000000000..8d912a65d
--- /dev/null
+++ b/.changeset/giant-days-develop.md
@@ -0,0 +1,7 @@
+---
+"@opennextjs/aws": patch
+---
+
+fix(http): Set content-length only if body is present
+
+The body is undefined when using the edge converter and the method is GET or HEAD
diff --git a/packages/open-next/src/http/request.ts b/packages/open-next/src/http/request.ts
index 88c68049e..35bc9e1b9 100644
--- a/packages/open-next/src/http/request.ts
+++ b/packages/open-next/src/http/request.ts
@@ -28,8 +28,10 @@ export class IncomingMessage extends http.IncomingMessage {
       destroy: Function.prototype,
     });
 
-    if (typeof headers["content-length"] === "undefined") {
-      headers["content-length"] = Buffer.byteLength(body).toString();
+    // Set the content length when there is a body.
+    // See https://httpwg.org/specs/rfc9110.html#field.content-length
+    if (body) {
+      headers["content-length"] ??= String(Buffer.byteLength(body));
     }
 
     Object.assign(this, {