diff --git a/src/runtime/app.ts b/src/runtime/app.ts
index 98d40fa913..d8327dab2c 100644
--- a/src/runtime/app.ts
+++ b/src/runtime/app.ts
@@ -80,7 +80,12 @@ function createNitroApp(): NitroApp {
   const regularHandlers = handlers.filter((h) => !h.formAction);
 
   if (formActionsHandlers.length > 0) {
-    const renderer = handlers.find(({ route }) => route === "/**");
+    const renderer = regularHandlers.find(({ route }) => route === "/**");
+    if (!renderer) {
+      throw new Error(
+        "[Form Actions]: Missing renderer. Please properly set `nitro.options.renderer`."
+      );
+    }
     const rendererHandler = lazyEventHandler(renderer.handler);
 
     for (const h of formActionsHandlers) {
diff --git a/test/fixture/actions/action.ts b/test/fixture/actions/action.ts
index fe577f6fc2..a30ab2a1c3 100644
--- a/test/fixture/actions/action.ts
+++ b/test/fixture/actions/action.ts
@@ -3,28 +3,55 @@ import {
   type EventHandler,
   type H3Event,
   defineEventHandler,
-  readBody
-} from 'h3'
+  readBody,
+} from "h3";
 
 interface Actions {
-  [key: string]: EventHandler
+  [key: string]: EventHandler;
 }
 
-function defineFormActions (actions: Actions) {
+function defineFormActions(actions: Actions) {
   return (event: H3Event) => {
-    const action = Object.keys(getQuery(event))[0]
-    const handler = action ? actions[action] : Object.values(actions)[0]
-    return defineEventHandler(handler(event))
+    const action = Object.keys(getQuery(event))[0];
+    const handler = action ? actions[action] : Object.values(actions)[0];
+    return defineEventHandler(handler(event));
+  };
+}
+
+async function respondWithResponse(event: H3Event, response: Response) {
+  // @ts-expect-error
+  for (const [key, value] of response.headers) {
+    event.node.res.setHeader(key, value);
   }
+
+  if (response.body) {
+    const contentType = response.headers.get("Content-Type") || "";
+    if (contentType.includes("text") || contentType.includes("json")) {
+      for await (const chunk of response.body as unknown as AsyncIterable<Uint8Array>) {
+        const stringChunk = new TextDecoder().decode(chunk); // Convert chunk to string
+        event.node.res.write(stringChunk);
+      }
+    } else {
+      // for binary data like images, videos, etc.
+      for await (const chunk of response.body as unknown as AsyncIterable<Uint8Array>) {
+        event.node.res.write(chunk);
+      }
+    }
+  }
+  return event.node.res.end();
 }
 
 function actionResponse(event: H3Event, data: any, action?: any) {
-  return { data, action }
+  // return { data, action };
+  return respondWithResponse(
+    event,
+    new Response(JSON.stringify({ data, action }))
+  );
 }
 
 export default defineFormActions({
-  default: async event => {
-    const body = await readBody(event)
-    return actionResponse(event, { ...body })
-  }
-})
+  default: async (event) => {
+    const body = await readBody(event);
+    return actionResponse(event, { ...body });
+  },
+});