diff --git a/.changeset/smart-grapes-shake.md b/.changeset/smart-grapes-shake.md
new file mode 100644
index 000000000..eb0e85ca0
--- /dev/null
+++ b/.changeset/smart-grapes-shake.md
@@ -0,0 +1,5 @@
+---
+"@opennextjs/aws": patch
+---
+
+fix: add cookies in express-dev wrapper
diff --git a/packages/open-next/src/overrides/wrappers/express-dev.ts b/packages/open-next/src/overrides/wrappers/express-dev.ts
index 7f861c462..9eb00dea3 100644
--- a/packages/open-next/src/overrides/wrappers/express-dev.ts
+++ b/packages/open-next/src/overrides/wrappers/express-dev.ts
@@ -26,7 +26,9 @@ const wrapper: WrapperHandler = async (handler, converter) => {
     const internalEvent = await converter.convertFrom(req);
     const streamCreator: StreamCreator = {
       writeHeaders: (prelude) => {
+        res.setHeader("Set-Cookie", prelude.cookies);
         res.writeHead(prelude.statusCode, prelude.headers);
+        res.flushHeaders();
         return res;
       },
       onFinish: () => {},