diff --git a/src/app.ts b/src/app.ts
index 636d4b2a..4d827a6e 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -231,5 +231,10 @@ function handleHandlerResponse(event: H3Event, val: any, jsonSpace?: number) {
     return send(event, JSON.stringify(val, undefined, jsonSpace), MIMES.json);
   }
 
+  // BigInt
+  if (valType === "bigint") {
+    return send(event, val.toString(), MIMES.json);
+  }
+
   return false;
 }
diff --git a/test/app.test.ts b/test/app.test.ts
index 38709293..880c09db 100644
--- a/test/app.test.ts
+++ b/test/app.test.ts
@@ -15,7 +15,7 @@ describe("app", () => {
   let request: SuperTest<Test>;
 
   beforeEach(() => {
-    app = createApp({ debug: false });
+    app = createApp({ debug: true });
     request = supertest(toNodeListener(app));
   });
 
@@ -29,6 +29,16 @@ describe("app", () => {
     expect(res.body).toEqual({ url: "/" });
   });
 
+  it("can return bigint directly", async () => {
+    app.use(
+      "/",
+      eventHandler(() => BigInt(9_007_199_254_740_991))
+    );
+    const res = await request.get("/");
+
+    expect(res.text).toBe("9007199254740991");
+  });
+
   it("can return Response directly", async () => {
     app.use(
       "/",